Answer:
107º
Step-by-step explanation:
Okay, if 135 is adjacent to an ungiven side, then to find that, you subtract 135 from 180.
180 - 135 = 45
So the other side is 45. Now we find the last unknown given side, and since we know 180 degrees is the sum of the degrees in a triangle, we do:
28 + 45 + x = 180
73 + x = 180
Subtract 73 on both sides you get,
x = 107.
Measure DEF is 107.
