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The base diameter of a cone is 10.5 cm and its slant height is 10 cm. Find its curved surface area. (π = $\frac{22}{7}$ )

Class 9Surface Area of a ConeMensuration

A $86.625 cm^{2}$
B $251.625 cm^{2}$
C $330 cm^{2}$
D $165 cm^{2}$

Step-by-Step Solution

r = 10.5 \div 2 = 5.25

cm. CSA =

\frac{22}{7} \times 5.25 \times 10 = 22 \times 0.75 \times 10 = 165 cm^{2} . (330 cm^{2}

uses the diameter as the radius.)

Answer: D)

165 cm^{2}

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