CBSE Class 10 Mathematics Standard 2024: question 35

Hints

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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. Perimeter of sector $=2r+\frac{\theta }{360^{\circ }}\times 2\pi r=20$ $\Rightarrow 11.2+2\times \frac{22}{7}\times 5.6\times \frac{\theta }{360^{\circ }}=20$

   2 marks

2. $\Rightarrow 35.2\times \frac{\theta }{360^{\circ }}=8.8\Rightarrow \theta =\frac{8.8\times 360^{\circ }}{35.2}=90^{\circ }$

   1 mark

3. Area of sector $=\frac{\theta }{360^{\circ }}\times \pi r^2=\frac{90}{360}\times \frac{22}{7}\times 5.6\times 5.6$

   1 mark

4. $=\frac{1}{4}\times \frac{22}{7}\times 31.36=24.64{\text{m}}^2$

   1 mark

Answer: 24.64 m²

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