Respuesta :

a = 65
b = 25
c = 25
d = 75

Explanation:

a = 180 - (60 + 55) = 180 - 115 = 65 (Angles on a straight line)

b = 90 - a = 90 - 65 = 25 (Angles in a right triangle)

c = b = 25 (Vertically Opposite Angles)

d = 90 - 15 = 75