In basic trigonometry to find the angle which is equal to its supplement we need to understand what are supplementary angles.

## Equal supplementary angles theorem

A supplementary angle is an angle which when added to another angle gives a total of 180 degree.

so supplementary of angle X degree= (180- X ) degree

Now we need to find a supplementary angle which is equal to X.

So in our case

X and its supplement ( 180 -X) are equal

X = (180-X)

2X= 180

X= 180/2

X= 90 Degree

#### Therefore The angle which is equal to its supplement is 90 Degree

#### Steps to solve similar problems:

If a question asks you to find supplementary angle then let x and y be the angles and then put their sum is 180 degrees

Similarly for complementary you seen to set the sum = 90 and then solve the equation.

For supplementary Y will be 180 – X

For complementary Y will be 90 -X

From the above equations you can find the value of X.

### FAQ

### What is Supplementary angles theorem ?

A supplementary angle is an angle which when added to another angle gives a total of 180 degree.

### What is the total of supplementary angles?

180 degree

### What is the difference between complementary and supplementary angles

Complementary- The sum of angles = 90

Supplentary – The sum of angles = 180