Question

I already know part b I just need help with A Please Help ASAP

Answer 1

< 3 + < 4 = 180 degrees ( adjacent angles)
<3 + 52 + 25 = 180 degrees (angles in a triangles) 
So if we subtract these 2 equations:-
<4 - (52 + 25) = 0

< 4 = 52 + 25