Isosceles Triangles

Grade 945 minutes

Learning Objective

I can calculate the missing angles or side lengths in an isosceles triangle.

Practice Questions

This lesson includes 7 practice questions to reinforce learning.

View questions preview

1. Define an isosceles triangle and explain the significance of its base angles.

2. In an isosceles triangle, if the lengths of the two equal sides are 7 cm each and the base is 10 cm, calculate the measure of the vertex angle.

3. Triangle DEF is an isosceles triangle where the base angles are each 45°. What is the measure of the vertex angle?

...and 4 more questions

Educational Video

Congruent legs and base angles of isosceles triangles | Congruence | Geometry | Khan Academy

Khan Academy

Create Your Own Lesson

Generate a custom lesson plan like this one in minutes with Insta~Lesson