Question

If one angle of a set of supplementary angles measures 77°, then the other angle measures _____.

Answer 1

then the other angle measures _1_0_3_.

Answer 2

If two angles are supplementary, then

the sum of their measures is 180°.

So if the measure of an angle is 77°,

the measure of its supplement is 103°.

We can find the measure of its supplement by taking 180 minus the measure of the original angle which in this case is 180 - 77 or 103°.