Question:
O is the centre of the circle, and AB is a chord. P is a point on AB. PA=3 centimeters, PB-8 centimeters, OP= 5 centimeters what is the radius of the circle?
A5.5 centimeters
B7 centimeters
C5 centimeters
D6.5 centimeters
Answer:
B. 7 centimeters
Explanation:
Extend OP to CD
OD = OC = r = radius of the circle
We know that
PA × PB = PC × PD
3 × 8 = (r - 5)(r + 5)
24 = r² - 5²
24 + 25 = r²
r² = 49
r = 7