Experiment with transformations in the plane High School | Students learn how shapes move, flip, and rotate on a flat surface. They explore what changes about a shape's position and what stays the same when it slides, reflects, or turns. | CCSS.Math.Content.HSG-CO.A |
Know precise definitions of angle, circle, perpendicular line, parallel line High School | Students learn the exact definitions of basic geometry terms: what makes lines parallel or perpendicular, how a circle is defined by distance from a center point, and what separates a line segment from an infinite line. | CCSS.Math.Content.HSG-CO.A.1 |
Represent transformations in the plane using, e.g., transparencies and geometry… High School | Students describe how shapes move, flip, or stretch on a flat grid, and sort those moves into two groups: ones that keep the shape the same size and angle, and ones that don't. | CCSS.Math.Content.HSG-CO.A.2 |
Given a rectangle, parallelogram, trapezoid High School | Students figure out which turns and flips leave a shape looking exactly the same as it started. A square, for example, can be rotated a quarter turn or flipped across its middle and still match up perfectly. | CCSS.Math.Content.HSG-CO.A.3 |
Develop definitions of rotations, reflections High School | Rotations, reflections, and translations each have precise definitions built from basic geometry: angles, circles, and lines. Students learn exactly what makes each movement work, not just what it looks like. | CCSS.Math.Content.HSG-CO.A.4 |
Given a geometric figure and a rotation, reflection High School | Students slide, flip, or rotate a shape on graph paper to a new position, then describe the exact steps that move one shape onto another. | CCSS.Math.Content.HSG-CO.A.5 |
Understand congruence in terms of rigid motions High School | Rigid motions are moves that slide, flip, or rotate a shape without changing its size. Students use these moves to show that two shapes are congruent, meaning they match exactly. | CCSS.Math.Content.HSG-CO.B |
Use geometric descriptions of rigid motions to transform figures and to predict… High School | Rigid motions are slides, flips, and turns that move a shape without changing its size or angles. Students use those moves to show whether two shapes are congruent, meaning one can land exactly on top of the other. | CCSS.Math.Content.HSG-CO.B.6 |
Use the definition of congruence in terms of rigid motions to show that two… High School | Two triangles are congruent when you can slide, flip, or rotate one to land exactly on the other. Students show this works only when every matching side and every matching angle between the two triangles are equal. | CCSS.Math.Content.HSG-CO.B.7 |
Explain how the criteria for triangle congruence High School | Two triangles are congruent when one can be moved exactly onto the other using flips, slides, and turns. ASA, SAS, and SSS are shortcuts that confirm this is possible without testing every point. | CCSS.Math.Content.HSG-CO.B.8 |
Prove geometric theorems High School | Students write logical, step-by-step arguments to show why rules about lines, angles, and triangles must be true. The goal is not just to know the answer but to explain why it works. | CCSS.Math.Content.HSG-CO.C |
Prove theorems about lines and angles High School | Students prove basic geometry rules from scratch, such as why vertical angles are equal or why a straight line always measures 180 degrees. The focus is on building a logical argument, not just stating the answer. | CCSS.Math.Content.HSG-CO.C.9 |
Prove theorems about triangles High School | Students prove why triangles behave the way they do, such as why the three angles always add up to 180 degrees or why the longest side always sits across from the largest angle. The focus is on building a logical argument, not just accepting the rule. | CCSS.Math.Content.HSG-CO.C.10 |
Prove theorems about parallelograms High School | Students prove that opposite sides of a parallelogram are equal, opposite angles match, and diagonals cut each other in half. The work moves from drawing and measuring to writing a logical argument that holds up every time. | CCSS.Math.Content.HSG-CO.C.11 |
Make geometric constructions High School | Students use a compass and straightedge to draw precise geometric shapes, like bisecting an angle or constructing a perpendicular line, without relying on measurement tools. | CCSS.Math.Content.HSG-CO.D |
Make formal geometric constructions with a variety of tools and methods High School | Students use a compass, straightedge, or folded paper to build precise geometric figures: copying a segment or angle, splitting a segment or angle in half, and drawing perpendicular or parallel lines. | CCSS.Math.Content.HSG-CO.D.12 |
Construct an equilateral triangle, a square High School | Using only a compass and straightedge, students draw a perfect triangle, square, or six-sided figure that fits exactly inside a circle, with every corner touching the edge. | CCSS.Math.Content.HSG-CO.D.13 |
Understand similarity in terms of similarity transformations High School | Similarity means two shapes are the same figure at different sizes or orientations. Students learn to describe that relationship using the moves, scaling, rotating, reflecting, that map one shape exactly onto the other. | CCSS.Math.Content.HSG-SRT.A |
Verify experimentally the properties of dilations given by a center and a scale… High School | Dilations stretch or shrink a figure from a fixed center point by a scale factor. Students test what stays the same (angles, shape) and what changes (side lengths) when they scale a figure up or down on the coordinate plane. | CCSS.Math.Content.HSG-SRT.A.1 |
A dilation takes a line not passing through the center of the dilation to a… High School | When a figure is stretched or shrunk from a fixed point, any line that doesn't run through that point shifts to a new position but stays parallel to where it started. Lines that do run through the fixed point stay put. | CCSS.Math.Content.HSG-SRT.A.1a |
The dilation of a line segment is longer or shorter in the ratio given by the… High School | Scale up or shrink a line segment, and its new length equals the original multiplied by the scale factor. Students use that ratio to find exact measurements after any dilation. | CCSS.Math.Content.HSG-SRT.A.1b |
Given two figures, use the definition of similarity in terms of similarity… High School | Two shapes are similar if one can be resized and repositioned to match the other exactly. Students decide whether two triangles are similar by checking that their matching angles are equal and their matching side lengths stay in the same ratio. | CCSS.Math.Content.HSG-SRT.A.2 |
Use the properties of similarity transformations to establish the AA criterion… High School | Two triangles are similar when two of their angles match. Students use that rule to prove triangles have the same shape even when one is larger or smaller than the other. | CCSS.Math.Content.HSG-SRT.A.3 |
Prove theorems involving similarity High School | Students use proportions and angle relationships to prove that two shapes are scaled versions of each other. The proofs appear in formal written arguments or diagrams showing why corresponding sides and angles must match. | CCSS.Math.Content.HSG-SRT.B |
Prove theorems about triangles High School | Students prove that a line drawn parallel to one side of a triangle cuts the other two sides proportionally. The work builds the logical case from scratch using what they already know about similar triangles. | CCSS.Math.Content.HSG-SRT.B.4 |
Use congruence and similarity criteria for triangles to solve problems and to… High School | Students use the rules for matching or scaling triangles to find missing side lengths and angles, then explain why those relationships hold in other shapes built from triangles. | CCSS.Math.Content.HSG-SRT.B.5 |
Define trigonometric ratios and solve problems involving right triangles High School | Trigonometric ratios connect the angles of a right triangle to the lengths of its sides. Students use sine, cosine, and tangent to find missing side lengths or angles in real situations like measuring a building's height or a ramp's slope. | CCSS.Math.Content.HSG-SRT.C |
Understand that by similarity, side ratios in right triangles are properties of… High School | The ratio between two sides of a right triangle stays the same whenever the angles stay the same. That consistent relationship is where sine, cosine, and tangent come from. | CCSS.Math.Content.HSG-SRT.C.6 |
Explain and use the relationship between the sine and cosine of complementary… High School | Sine and cosine are linked: the sine of any angle equals the cosine of its complement. Students use this to swap between the two when solving triangle problems, without recalculating from scratch. | CCSS.Math.Content.HSG-SRT.C.7 |
Use trigonometric ratios and the Pythagorean Theorem to solve right triangles… High School | Given a real situation with a right triangle, such as finding the height of a building or the distance across a river, students use sine, cosine, tangent, and the Pythagorean Theorem to find the missing side lengths and angles. | CCSS.Math.Content.HSG-SRT.C.8 |
Apply trigonometry to general triangles High School | Students use sine, cosine, and tangent to find missing side lengths and angles in triangles that don't have a right angle. This includes the Law of Sines and the Law of Cosines. | CCSS.Math.Content.HSG-SRT.D |
(+) Derive the formula A = 1/2 ab sin High School | Students learn where the triangle area formula A = 1/2 ab sin(C) actually comes from. By dropping a perpendicular line from one corner to the opposite side, they build the formula from scratch instead of just memorizing it. | CCSS.Math.Content.HSG-SRT.D.9 |
(+) Prove the Laws of Sines and Cosines and use them to solve problems High School | Using the Laws of Sines and Cosines, students find missing side lengths and angles in any triangle, not just right triangles. They also work through the reasoning that proves why those formulas hold. | CCSS.Math.Content.HSG-SRT.D.10 |
(+) Understand and apply the Law of Sines and the Law of Cosines to find… High School | Given a triangle where some sides or angles are unknown, students use the Law of Sines and Law of Cosines to find the missing measurements. This applies to any triangle, not just ones with a right angle. | CCSS.Math.Content.HSG-SRT.D.11 |
Understand and apply theorems about circles High School | Circles follow predictable rules about angles, arcs, and line segments. Students learn those rules and use them to solve problems involving chords, tangents, and the relationships between parts of a circle. | CCSS.Math.Content.HSG-C.A |
Prove that all circles are similar High School | Students show why any two circles are always the same shape, just different sizes, by explaining that you can always scale one circle up or down to match the other exactly. | CCSS.Math.Content.HSG-C.A.1 |
Identify and describe relationships among inscribed angles, radii High School | Inscribed angles, radii, and chords all follow predictable rules inside a circle. Students learn those rules and use them to find missing angles and lengths. | CCSS.Math.Content.HSG-C.A.2 |
Construct the inscribed and circumscribed circles of a triangle High School | Students learn to draw the largest circle that fits inside a triangle and the smallest circle that wraps around it. They also prove why opposite angles in a four-sided shape drawn inside a circle always add up to 180 degrees. | CCSS.Math.Content.HSG-C.A.3 |
(+) Construct a tangent line from a point outside a given circle to the circle High School | Given a point outside a circle, students draw a line that just grazes the circle's edge at exactly one spot. This construction uses a compass and straightedge, with no guessing. | CCSS.Math.Content.HSG-C.A.4 |
Find arc lengths and areas of sectors of circles High School | Students calculate how long a curved slice of a circle's edge is, and how much area a pie-slice section covers. Both answers depend on the angle at the center and the size of the circle. | CCSS.Math.Content.HSG-C.B |
Derive using similarity the fact that the length of the arc intercepted by an… High School | Students learn why a bigger circle stretches an arc by the same factor it stretches the radius, then use that relationship to define radian measure and calculate the area of a pie-slice section of any circle. | CCSS.Math.Content.HSG-C.B.5 |
Translate between the geometric description and the equation for a conic section High School | Students connect the shape of a curve (a circle, parabola, or ellipse) to its equation, and work in both directions: starting from a graph to write the equation, or starting from an equation to sketch the curve. | CCSS.Math.Content.HSG-GPE.A |
Derive the equation of a circle of given center and radius using the… High School | Students use the Pythagorean Theorem to build the equation of a circle from its center point and radius. They also work backward, rewriting a given equation to figure out where the circle sits and how wide it is. | CCSS.Math.Content.HSG-GPE.A.1 |
Derive the equation of a parabola given a focus and directrix High School | Students learn where a parabola comes from by using two geometric pieces: a fixed point and a fixed line. They write the equation that describes every point on the curve that sits exactly halfway between those two references. | CCSS.Math.Content.HSG-GPE.A.2 |
(+) Derive the equations of ellipses and hyperbolas given the foci, using the… High School | Given two fixed points called foci, students figure out the equation of an ellipse or hyperbola by using the rule that the distances from any point on the curve to those two foci always add up to (or differ by) the same number. | CCSS.Math.Content.HSG-GPE.A.3 |
Use coordinates to prove simple geometric theorems algebraically High School | Students use x-y coordinates to prove geometric facts, like showing two lines are parallel or that a shape's diagonals bisect each other, without relying on a diagram alone. | CCSS.Math.Content.HSG-GPE.B |
Use coordinates to prove simple geometric theorems algebraically High School | Students use x-y coordinates to prove geometry facts with algebra instead of diagrams. For example, they might show that a shape is a rectangle by calculating slopes to confirm its angles are right angles. | CCSS.Math.Content.HSG-GPE.B.4 |
Prove the slope criteria for parallel and perpendicular lines and use them to… High School | Parallel lines have equal slopes; perpendicular lines have slopes that are negative reciprocals of each other. Students use those two rules to write equations for lines that run alongside or cut straight across a given line through a specific point. | CCSS.Math.Content.HSG-GPE.B.5 |
Find the point on a directed line segment between two given points that… High School | Students find the exact spot on a line segment that divides it into two pieces with a specific size relationship, like cutting a road into a one-third and two-thirds split. They use coordinates and ratios to locate that point precisely. | CCSS.Math.Content.HSG-GPE.B.6 |
Use coordinates to compute perimeters of polygons and areas of triangles and… High School | Students use the x-y coordinates of a shape's corners to calculate how far around the outside it measures and how much space it covers inside. The work leans on the distance formula to find side lengths first. | CCSS.Math.Content.HSG-GPE.B.7 |
Explain volume formulas and use them to solve problems High School | Students learn where volume formulas come from and use them to find how much space a solid shape holds. They apply those formulas to solve real problems involving cylinders, cones, pyramids, and spheres. | CCSS.Math.Content.HSG-GMD.A |
Give an informal argument for the formulas for the circumference of a circle… High School | Students explain in their own words why the formulas for circle circumference, circle area, and the volumes of cylinders, pyramids, and cones actually work, not just how to use them. | CCSS.Math.Content.HSG-GMD.A.1 |
(+) Give an informal argument using Cavalieri's principle for the formulas for… High School | Students explain why the volume formulas for spheres and cones actually work by showing that two solids with matching cross-sections at every height must have equal volumes. It's the geometric reasoning behind the numbers, not just the formula itself. | CCSS.Math.Content.HSG-GMD.A.2 |
Use volume formulas for cylinders, pyramids, cones High School | Students apply volume formulas to find how much space fits inside cylinders, cones, pyramids, and spheres. The problems go beyond plugging in numbers, asking students to work backward or combine shapes to find a missing measurement. | CCSS.Math.Content.HSG-GMD.A.3 |
Visualize relationships between two-dimensional and three-dimensional objects High School | Students practice seeing how flat shapes and solid objects connect. For example, rotating a rectangle creates a cylinder, and slicing a cone with a flat cut reveals a circle. | CCSS.Math.Content.HSG-GMD.B |
Identify the shapes of two-dimensional cross-sections of three-dimensional… High School | Slice a cone or a cylinder with an imaginary cut and name the flat shape you see. Students also figure out what solid a flat shape would form if you spun it around an axis. | CCSS.Math.Content.HSG-GMD.B.4 |
Apply geometric concepts in modeling situations High School | Students use shapes, measurements, and spatial reasoning to solve real-world problems, like figuring out how much paint covers a wall or how much space fits inside a building. | CCSS.Math.Content.HSG-MG.A |
Use geometric shapes, their measures High School | Real objects can be described using basic shapes. Students practice seeing a tree trunk as a cylinder or a room as a rectangular box, then use the measurements of that shape to solve practical problems. | CCSS.Math.Content.HSG-MG.A.1 |
Apply concepts of density based on area and volume in modeling situations High School | Density problems ask students to figure out how much of something fits into a given space. For example, students might calculate how many people live per square mile or how much heat energy fills a room. | CCSS.Math.Content.HSG-MG.A.2 |
Apply geometric methods to solve design problems High School | Students use geometry to solve real design problems, like figuring out the best shape for a structure or the most efficient layout for a space. The math has a practical goal: meet a constraint, cut a cost, or make something fit. | CCSS.Math.Content.HSG-MG.A.3 |