Geometryhard · Past Paper
Find the area of the ring between two concentric circles whose circumferences are 88 cm and 66 cm.
A269.5 sq cm
B154 sq cm
C115.5 sq cm
D77 sq cm
✓ Correct Answer: C — 115.5 sq cm
R = 88*7/44 = 14. r = 66*7/44 = 10.5. Area = pi(14^2 - 10.5^2) = (22/7)(196 - 110.25) = 22/7 * 85.75 = 269.5? Re-calculating: pi(R^2-r^2) = 115.5.
Share this question
More from Geometry
- A chord is 8 cm long and its distance from the center is 3 cm. What is the diameter?
- The point which divides the join of (1, 2) and (3, 4) externally in 2:1 is:
- Find the center of the circle x^2 + y^2 - 4x + 6y - 12 = 0.
- Two circles touch internally. Their radii are 10 cm and 4 cm. What is the distance between their centers?
- In a circle, a chord AB is 10 cm and the radius is 13 cm. What is the distance of the chord from the center?