Exterior and Interior Angle Theoerm
Tenth graders investigate triangles. In this geometry lesson, 10th graders explore the relationship between an exterior angle of a triangle and the remote interior angle. The dynamic nature of Cabri Jr. allows for conjecture and verification.
10th Math 3 Views 6 Downloads
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...
9th - 10th Math CCSS: Designed
New Review Inscribing and Circumscribing Right Triangles
High schoolers attempt an assessment task requiring them to find the radii of inscribed and circumscribed circles of a right triangle with given dimensions. They then evaluate provided sample responses to consider how to improve their...
9th - 12th Math CCSS: Designed
Joining Two Midpoints of Sides of a Triangle
Without ever using the actual term, this exercise has the learner develop the key properties of the midsegment of a triangle. This task leads the class to discover a proof of similar triangles using the properties of parallel lines cut...
9th - 11th Math CCSS: Designed
Congruence, Proof, and Constructions
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs. Each of the almost-forty lessons is broken...
8th - 10th Math CCSS: Designed
New Review Geometry: Angles, Triangles, and Distance
The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.
7th - 10th Math CCSS: Designed