Multiple choice

Two mutually perpendicular chords AB and CD intersect at P. AP = 4 units, PB = 6 units, CP = 3 units. Find the radius of the circle.

  1. 31.251/2 units

  2. 13.251/2 units

  3. 24.251/2 units

  4. 52.251/2 units

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

By the intersecting chords theorem, CP x PD = AP x PB, so 3 x PD = 4 x 6 and PD = 8. Using the chord endpoints, the circle has center (1, -5/2), giving radius sqrt(31.25), which is the value represented by option A.