Answer:
Addition and subtraction can be used to put together and separate the measures of an angle and the parts of the angle by using the angles given to check for the supplementary or complementary angles as the case may be.
Angles are parts or sections of a complete circle. When a circle is divided into different angles, and the angles are now placed together, their sum will be 360 degrees. Complementary angle is gotten when the sum of two different angles have a total of 90 degress while supplementary angle is when the sum of two different angles is 180 degrees.
Example:
We have,
X + 80 = 180
X = 180 - 80
X = 100°
This is a case of looking for the other angle in a supplementary angle, when the value of one angle is 80 degrees.