The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...

Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...

Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...

Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...

Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation. 

The class braids irrational numbers, Pythagoras, and perimeter together. The mini-assessment requires scholars to use irrational numbers and the Pythagorean Theorem to find perimeters of rugs. The rugs are rectangular, triangular,...

Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...

You're safe, when calculating the odds of stealing second base! Learners compare the rate of a runner to the distance the ball travels, in a lesson that explores right triangles and measurement. Full of discussion questions and fun...

Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...

Discover some theorems about triangles.

Find the missing side lengths of isosceles triangles by using the Pythagorean Theorem. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.

[Free Registration/Login may be required to access all resource tools.] Here you'll learn what an isosceles right triangle is, the relationships between the sides of an isosceles right triangle, and how to find the length of an unknown...