Question

Line CD is tangent to circle A at point B. Segment AB is a radius of circle A. What can be concluded about angle ABD?

Answer 1

Segment AB is a radius of circle A. We can conclude that angle ABD is complementary to angle ABC. The answer is letter C. Complementary angles are angles that forms 90 degrees. Since the line CD is tangent to circle A at point B and the distance of line CB is the same as that in line BD then it forms a perpendicular line at point B which divides both angle in 90 degrees.