Question

if one of two supplementary angles has a measure of 121 degrees what is the measure of the other angle?

Answer 1

The measure of the other angle is 59°

Explanation:

Supplementary Angles

Two angles
`\alpha` and
`\beta` are supplementary when they add up to 180 degrees, i.e.

`\alpha+\beta=180^o`

One notable property is that together they make a straight angle although they don't have to be together to be supplementary.

We are given one of two supplementary angles with a value of 121 degrees, we can compute the measure of the other angle, say
`\alpha` as

`\alpha=180^o-\beta=180^o-121^o=59^o`

The measure of the other angle is 59°