If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Angles

4 videos
4 skills
Let's complement and supplement our knowledge of angles with some new geometry vocabulary. In this group of tutorials you'll learn about complementary, supplementary, vertical, adjacent, and straight angles. You'll quickly realize that the relationship between each of the angle types is quite logical and solving problems involving intersecting lines is a snap. Onward! Common Core Standards: 7.G.B.5

Complementary and supplementary angles

VIDEO 8:31 minutes
Let's add some tools to our geometry tool belt. Here's a thorough explanation of complementary and supplementary angles, as well as definitions of adjacent and straight angles.

Introduction to vertical angles

VIDEO 7:19 minutes
By using our knowledge of supplementary, adjacent, and vertical angles, we can solve problems involving the intersection of two lines. Including this one!

Vertical angles

PRACTICE PROBLEMS

Find measure of vertical angles

VIDEO 3:00 minutes
Given two intersecting lines and the measure of vertical angles, watch as we solve to find the measure of the remaining angles.

Find measure of angles in a word problem

VIDEO 4:34 minutes
Solve this word problem to find the measure of angles. In this example you'll split up a pie (don't forget to share!)

Solving for unknown angles

PRACTICE PROBLEMS

Quadrilateral angles

PRACTICE PROBLEMS