NCERT Solutions · Class 10 Mathematics Areas Related to Circles

A car has two wipers which do not overlap. Each wiper has a blade of length $\displaystyle 25$ cm sweeping through an angle of $\displaystyle 115$°. Find the total area cleaned at each sweep of the blades.

To warn ships for underwater rocks, a lighthouse spreads a red coloured light over a sector of angle $\displaystyle 80$° to a distance of $\displaystyle 16.5$ km. Find the area of the sea over which the ships are warned. (Use $\displaystyle \pi=3.14$ )

A round table cover has six equal designs as shown in Fig. 11.11. If the radius of the cover is $\displaystyle 28$ cm, find the cost of making the designs at the rate of ₹ $\displaystyle 0.35$ per $\displaystyle \mathrm{cm}^{2}$. (Use $\displaystyle \sqrt{3}=1.7$ )

Tick the correct answer in the following : Area of a sector of angle $\displaystyle p$ (in degrees) of a circle with radius R is (A) $\displaystyle \frac{p}{180} \times 2 \pi \mathrm{R}$ (B) $\displaystyle \frac{p}{180} \times \pi \mathrm{R}^{2}$ (C) $\displaystyle \frac{p}{360} \times 2 \pi \mathrm{R}$ (D) $\displaystyle \frac{p}{720} \times 2 \pi \mathrm{R}^{2}$