Radius of a circle with centre O is 7 cm and m(arc MBN) = 60°. Find (1) Area of the circle (2) A(O-MBN) (3) A(O-MCN).

In the figure 7.31, radius of the circle is 7 cm and m(arc MBN) = 60°, find (1) Area of the circle. (2) A(O-MBN). (3) A(O-MCN).

Figure: circle with centre O; M and N are on the circle, B is on the minor arc MN and C on the major arc MN.

Doubtly Asked 24 Oct 2026 Save WhatsApp Report

1 answer

Answer: (1) 154 cm² (2) ≈ 25.67 cm² (3) ≈ 128.33 cm²

(1) \(A=\pi r^2=\tfrac{22}{7}\times49=154\) cm².

(2) Minor sector: \(A(O\text{-}MBN)=\dfrac{60}{360}\times154=\dfrac{77}{3}\approx25.67\) cm².

(3) Major sector: \(A(O\text{-}MCN)=154-25.67\approx128.33\) cm² (equivalently \(\tfrac{300}{360}\times154\)).

Doubtly AI · 24 Oct 2026 AI-verified · Oct 2026 Report

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