# >> K-12 >> K-12 Basics

How to Find the Length of an Angle

Angles are everywhere. Our very existence in three-dimensional space depends on them. In geometry, angles abide by certain rules and can be calculated using these principles. Angles are measured in degrees, the maximum of which is 360 and the minimum is any number greater than zero. You can measure angles using a simple tool called a protractor or mathematically by applying the principles of geometry.

Instructions

- 1
  Line the protractor up with the angle. Position the bottom center of the protractor at the base of the angle.
- 2
  Note at which point the angle crosses the hash marks on the protractor. This is the angle value.
- 3
  Deduce the angle from its relation to a geometric shape. In triangles, the sum of the angles is 180 degrees. If you know two angles, you can deduce their sum from 180 to find the third.
- 4
  Remember that a right angle is always 90 degrees.
- 5
  Subtract one angle from 180 degrees if two angles lie on a straight line. This is because a straight line is always 180 degrees. Therefore, if you know one angle, you can calculate its complement (the one that sits adjacent to the other angle.)

How to Stop Sleeping in Class

Primary Research Techniques