Question

question 3 of 10
if the blue radius below is perpendicular to the green chord and the segment
ab is 9 units long, what is the length of the chord?
a. 9 units
b. 27 units
c. 4.5 units
d. 18 units

Explanation:

Step1: Recall circle - chord property

A radius perpendicular to a chord bisects the chord.

Step2: Determine chord length

Since the radius is perpendicular to chord $AC$ and $AB = 9$ units, and the radius bisects the chord, $AC=2\times AB$.
So, $AC = 2\times9=18$ units.

Answer:

D. 18 units