Question

Two angles are supplementary. Which of the following equations can be used to find the value of the missing angle, x, if the other angle is 98°?

Answer 1

Two angles are said to be supplementary if their sum is 180 degrees. So, if x and y are supplementary angles, the formula is

$x + y = 180$

We know that one of the angles (say x) is 98. So, the equation updates to

$98 + y = 180$

If we want to solve for the other angle, we can simply subtract 98 from both sides to get

$y = 180-98 = 82$