Which definition can be used to help prove the theorem below? If a line is tangent to a circle, then it is perpendicular to the radius drawn to the point of tangency.

A) perpendicular lines are two lines which intersect to form right angles
B) if two lines are perpendicular, then they intersect to form four right angles
C) the shortest distance between a point and a line is a perpendicular line segment
D) the foot of a perpendicular from a point to lie is the point where the perpendicular meets the line.

1 Answer
Jun 27, 2018

I'd say (C); it's the only one that concludes with "and the line is a perpendicular" which is what we want to prove. The closest point to the center of a circle from a line tangent to a circle is the tangent point.