Can anybody help me solve this ?

77*

First we are going to take our given number, 25* and 78* and add them together.

25* + 78* = 103*

And subtract our answer, 103*, from 180*.

180* - 103* = 77*

77* is our missing angle. To prove it, we add angle measures a, b, and c, to make the number 180*

25* + 78* + 77* = 180*

Another way to write it is . . .

180* - (A + B) = C

~Hope this helps~

knlknlkkn

step-by-step explanation: