If you're seeing this message, it means we're having trouble loading external resources on our website.

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

## Basic geometry and measurement

### Course: Basic geometry and measurement>Unit 3

Lesson 5: Measuring angles

# Constructing angles review

Review constructing angles with a protractor, then try constructing some of your own.

## Constructing angles

We can use a protractor to help us construct an angle of a given amount of degrees.
Example
Construct a 65, degrees angle.
To make a 65, degrees angle, we move the middle dot of the protractor to the vertex (where the 2 rays connect) of the angle.
A protractor shows points plotted at 160 and 180 degrees. Rays go out from a vertex at the protractor's center and through each point.
Next, we line up one of the rays on the 0, degrees line of the protractor.
A protractor shows points plotted at 0 and 180 degrees. Rays go out from a vertex at the protractor's center and through each point.
We then move the other ray around until it is lined up with the 65, degrees measurement on the protractor.
A protractor shows points plotted at 0 and 65 degrees. Rays go out from a vertex at the protractor's center and through each point.
The angle will look like this when the measurement is 65, degrees. Note: The angle can be rotated in any direction, but the angle between the two rays must look like this.
An angle is formed by two rays extending out from a common point. The size of the angle is the same as in the previous image.