Answer:
- a = 65°
- b = 25°
- c = 25°
- d = 75°
Step-by-step explanation:
The sum of angles that make up a linear angle is 180°, so we have ...
60 + a + 55 = 180
a = 65 . . . . . . . . . . . . . . subtract 115
The acute angles in a right triangle are complementary, so we have ...
b = 90 -65 = 25
Vertical angles are congruent, so ...
c = b = 25
___
Angle d is the complement of the one marked 15, so its measure is ...
d = 90 -15 = 75
The angle measures are ...
a = 65°
b = 25°
c = 25°
d = 75°
