All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the lesson.

An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...

Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 

Explains the basic concept of isosceles triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

[Free Registration/Login may be required to access all resource tools.] This study guide reviews terminology for triangles, triangle properties, different types of triangles, and interior and exterior angle theorems.

[Free Registration/Login may be required to access all resource tools.] Different types of right triangles and trigonometric ratios for special right triangles are covered in this study guide.

This study guide on bisectors, medians, and altitudes covers key vocabulary, different theorems, and facts about the altitude and triangles. It is available for download with free registration.