XOY is a real sector of a circle center O of radius 3.5cm which subtends an angle of 144o at the center. Calculate, in term of \(\pi\), the area of the sector
- 1.4\(\pi\)cm2
- 2.8\(\pi\)cm2
-
4.9\(\pi\)cm2
- 9.8\(\pi\)cm2
The correct answer is: C
Explanation
Area of a sector \(=\frac{\theta}{360}\times \pi r^2\\
\left(\frac{144}{360}\times \pi \times \frac{3.5}{1} \times 3.5\right)cm^2 = 4.9\pi cm^2\)