In the diagram below, O is the center if the two concentric circle of radii...
MATHEMATICS
WAEC 1998
In the diagram below, O is the center if the two concentric circle of radii 13cm and 10cm respectively. Find the area of the shaded portion in the sector with angle 1200 at the center
- A. \(\frac{1}{3}\pi cm^2\)
- B. \(\pi cm^2\)
- C. \(3\pi cm^2\)
- D. \(23\pi cm^2\)
Correct Answer: D. \(23\pi cm^2\)
Explanation
\(\frac{120\pi}{360}(R^2 - r^2)\\
\frac{1}{3}\times \pi (13^2 - 10^2)\\
\frac{1}{3}\times \pi \times 69 = 23\pi cm^2\)
Post an Explanation Or Report an Error
If you see any wrong question or answer, please leave a comment below and we'll take a look. If you doubt why the selected answer is correct or need additional more details? Please drop a comment or Contact us directly. Your email address will not be published. Required fields are marked *