What are angles?

  • An angle is a way of describing the space between 2 lines that begin at the same point. An angle is a measure of how much you have to turn one of the lines so that it perfectly overlaps with the other.

  • An angle is measured in degrees (°) using a protractor.

  • Angles can be measured anywhere from 0° to 360°. It is possible to estimate angles.

A short video explaining the concept of angles.

Types of angle

An angle is how much one line is turned or rotated from another. The lines do not have to be the same length and it doesn’t matter which way they are turned, but they must start at the same point. Angles are given different names according to how big they are:

  • less than ¼ turn is an acute angle

  • between ¼ and ½ turn is an obtuse angle

  • more than ½ turn is a reflex angle.

Angles are measured in degrees using a protractor. There are some special angles that are useful to remember...

  • a ¼ turn or right angle = 90°

  • a ½ turn or straight line = 180°

  • 1 turn or full turn or angle around a point = 360°. There are 360° in a circle.

Two straight lines that cross at one point, to make an X shape, create two pairs of opposite angles that are equal to each other.