Measuring Angles
An angle can be measured using a protractor, precisely.An angle is measured in degrees, hence its called ‘degree measure’.
One complete revolution is equal to 360 degrees, hence it is divided into 360 parts. Each part of the revolution is a degree.
Any angle whether it is acute, obtuse, reflex, or right angle, can be measured using a protractor.
How to Measure angles using Protractor
The above picture shows a protractor. Seen
A protractor is a semi-circular tool used to draw and measure angles.
It is marked with degrees from 0 to 180 degrees.
It can be directly used to measure any angle from 0 to 360 degrees.
The markings are made in two ways, 0 to 180 degrees from right to left and vice versa.
To measure an angle using a protractor, follow the steps below.
1) Line up the vertex of the angle with the dot at the center of the protractor.
2) Line up one side of the angle with 0 degrees on the protractor.
3) Read the protractor to see where the other side of the angle crosses the number scale.
Note - Most protractors have two number scales. It's important to use the same number scale for both sides of the angle.
Inner Number Scale
One side of this angle is lined up with 0 degrees on the inner number scale of the protractor.
Read the inner number scale where the other side crosses.
This angle measures 120 degrees, or
120°.
Outer Number Scale
One side of this angle is lined up with 0 degrees on the outer number scale of the protractor.
Read the outer number scale where the other side crosses.
This angle measures 35 degrees, or
35°.
Note -
When the baseline is towards right side follow the inner number scale and when the baseline is towards left side follow the outer number scale.