Angles

This course is a part of Geometry (all content), a 17-course Topic series from Khan Academy.

In this topic, we will learn what an angle is and how to label, measure and construct them. We will also explore special types of angles.

This course contains 8 segments:

Angle introduction

What is an angle and how do we label, measure and construct them? Great question. Luckily we have all your answers! To begin our journey towards understanding angles, we'll learn terms like vertex, acute, obtuse, circle arc, circumference, and protractor. These basic angle concepts will get you on the road to angle domination!

Measuring angles

Learn how to measure angles using a protractor.

Constructing angles

Learn how to draw angles using a protractor.

Angles in circles

Learn how to measure angles using a circle protractor and solve word problems about angles as part of a circle.

Angle types

Now that we know what angles are, let's dig a bit deeper and classify them and understand their properties better. Acute, obtuse, right, adjacent--all are angles that we will be become familiar with.

Vertical, complementary, and supplementary angles

Learn three types of angle pairs: vertical angles, complementary angles, and supplementary angles.

Angles between intersecting lines

This tutorial introduces us to angles. It includes how we measure them, how angles relate to each other and properties of angles created from various types of intersecting lines. Mr. Angle is actually far more fun than you might initially presume him to be.

Sal's old angle videos

These are some of the classic, original angle video that Sal had done way back when (like 2007). Other tutorials are more polished than this one, but this one has charm. Also not bad if you're looking for more examples of angles between intersected lines, transversals and parallel lines.