Question #N372
A circle has a radius of 5 cm. A chord of the circle is 8 cm long. What is the distance, in cm, from the center of the circle to the chord?
A. 2
B. 3
C. 4
D. 5
Correct Answer is: B
Draw a radius from the center of the circle to each endpoint of the chord. This creates an isosceles triangle with a base of 8 cm and two sides of 5 cm. Draw the altitude from the center of the circle to the chord. This altitude bisects the base of the isosceles triangle, creating two right triangles with a hypotenuse of 5 cm and a leg of 4 cm. Using the Pythagorean Theorem, the other leg of the right triangle (which is the distance from the center of the circle to the chord) is cm.