Curated OER
A Rectangle in the Coordinate Plane
A quadrilateral is drawn on the coordinate plane, and eighth grade geometers find the length of each side and the diagonals by applying the Pythagorean theorem.
EngageNY
Locating Ordered Pairs on the Coordinate Plane
Four quadrants, four times the fun. Future mathematicians learn the terminology associated with the coordinate plane and how to plot points in all four quadrants. A worksheet tests their understanding of the material in the 16th...
CK-12 Foundation
Distance Between Two Polar Coordinates: Exploring Changes in Angle and Radius
Get straight answers on a curved grid. An interactive has learners apply the Law of Cosines to find the distance between two points on the polar coordinate plane. The pupils use the radii lengths and the angle between the two radii to...
Mathed Up!
Rotation
Two videos show first how to perform a rotation, given the center, the angle, and the direction of rotations. Individuals then see how to find what the rotation is from one figure to another. Pupils practice doing both in seven problems...
Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Mt. San Antonio Collage
Graphing Trigonometric Functions
Double win with a comprehensive worksheet and an excellent worked out answer key. The worksheet itself is twelve pages and begins with the simple sine and cosine graphs, then, develops into the reciprocal trig functions.
Mathematics Vision Project
Module 6: Congruence, Construction, and Proof
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This unit...