# How to Measure an Angle

Updated on April 7, 2012

## What tool is used to measure an Angle?

You will need a protractor in order to measure an angles

What is a protractor?

A protractor is a mathematical tool that helps us determine an angles measure.

## How to measure an Angle

The first thing that we need to do it identify some pieces of the angle we are about to measure.

The first thing we need is the vertex of the angle.

The vertex is the point where two lines meet to create an angle or intersection.

I have highlighted the vertex as a red point in picture #2.

The other item I need is the base line that I am going to use as the starting point as a 0.

I am going to place my protractor on top of the angle and line the vertex with the middle cross of the protractor.

I then rotate the protractor so that the green line is lined up with the zero line on the protractor.

I can now measure the protractor.

The yellow highlighting shows the area that I am reading in order to measure the angle.

This angle is 65°

## Measure the Angles

Measuring Angles can be a simple process but many students get confused when it comes to the double row of numbers. Just remember that you always need to start measuring at the zero place and go up from there. This angle could not be a measure of 115° because that would not start at the zero place to measure. Also be sure to use your common sense and classification of triangles. This is clearly an acute angles which means the measure must be between 0° and less than 90°.

60

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59