Answer:
b = 108
c = 72
Explanation:
The triangle formed by the two tangents is an isosceles triangle.
180 - 72 = 108
108/2 = 54
The other two angles in the triangle are equal to 54 degrees.
A tangent always meets the radius line at a right angle. Therefore, the radius line (between b and c) meets the tangent at 90 degrees.
90 - 54 = 36
Therefore the other two angles of 'b' triangle are equal to 36 degrees.
36 x 2 = 72
180 - 72 = 108
b = 108
And therefore b is equal to 108 degrees.
b + c = 180 (because a straight line is always equal to 180 degrees)
180 - 108 = 72
So c = 72