All three sides always add up to 360 so add the given measures and subtract it from 360 and that would give you your answer.
An angle that measures 1/2 turn is 180 degree angle
Slope = rise/run = (change in y)/(change in x)
Slope = (4-6)/(0-(-4)) = (-2)/(4)
Slope = -1/2 = -0.5
F(x) = -3x + 7
y = -3x + 7
x = -3y + 7
-3y + 7 = x
-3y = x - 7
y = -1/3x + 7/3
f^-1(x) = -1/3x + 7/3