Question

What is the measure of angle BCD?


35

55

90

125

Answer 1

The measure of an exterior angle is the same as the sum of the remote interior angles (35+90) [in a plane].

Answer 2

180-(90-35)

Answer 3

125

Answer 4

That's another good way to do it.^

Answer 5

sum of all the angles of a triangle is 180 degree.
hence 35 + 90 + angle BCA =180
125 + angle BCA = 180
angle BCA = 180 - 125
angle BCA = 55 degree
now see angle BCA and BCD are forming linear pair
hence angle BCA + angle BCD = 180
55 + angle BCD = 180
angle BCD = 180-55
angle BCD = 125 degree