CBSE Class 10 Mathematics Standard 2023: question 29

Hints

Open one hint at a time and try again before the next.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

1. Each blade sweeps a sector with $r=21$ cm and $\theta =120^{\circ }$.
   Area of one sector $=\frac{\theta }{360^{\circ }}\times \pi r^2=\frac{120^{\circ }}{360^{\circ }}\times \frac{22}{7}\times 21\times 21$

   1½ marks

2. $=462{\text{cm}}^2$

   1 mark

3. The wipers do not overlap, so total area cleaned $=2\times 462=924{\text{cm}}^2$.

   ½ mark

Answer: 924 cm²

Revise the chapter

• Chapter: Areas Related to Circles (notes, formulas, where marks are lost and every past question)
• Topic: Area of a Sector of a Circle