Angle a has a little square box in it, which means right angle, which is equal to 90 degrees.
Angle A = 90 degrees
Angle A m B and the 59 forms a straight line which needs to equal 180
Angle B = 180 - 59 - 90 = 31
Angle B = 31 degrees.
Angle C is a vertical angle with A and B, so Angle C = 90 + 31 = 121 degrees.
Angle D is a vertical angle with 59, so equals 59 degrees.