Okay so this is fun, let's lable the angle just under 72, but still on the right side B. now, side b is corresponding or equal to (2y+48). So you set them to equal 180 because it makes a straight line....
(2y+48) + 72 = 180
2y + 48 + 72 = 180
2y + 120 = 180
2y = 180 - 120
2y = 60
y = 60/2
y = 30
plug this back in and ...
2(30)+48 =
(60+48) =
108
No we'll use 108 + 72 to make sure that the y is correct and....
