Question

Find the total surface area of a cone, if its slant height is 21 m and diameter of its base 24m​

Answer 1

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• Find the total surface area of a cone, if its slant height is 21m and diameter of its base 24m.

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Given:-

$\sf{ \rightarrow {Slant \: height \: of \: the \: cone = 21m }}\\ \\ \sf{ \rightarrow{Diameter \: of \: its \: base = 24m}}$

To find:-

$\sf{ \rightarrow{Total \: serface \: area \: of \: the \: cone}}$

❣ Solution:-

In the given question,

Diameter of the cone = 24m.

Therefore, radius of the cone = (24÷2)m = 12m

We know that,

Total surface area:-

$\boxed{ \sf{ \blue{T.S.A.= \pi \: r(r + l)}}}$

According to the question,

$\sf{ \bold{T.S.A.}} = \pi \times 12(21 + 12) \\ \\ \rightarrow{ \sf{TSA = \frac{22}{7} \times 12(33)}} \\ \\ \rightarrow{ \sf{TSA = \frac{22}{7} \times 396}} \\ \\ \rightarrow{ \sf { \orange{TSA= 1,244.57}}}$

$\underline{ \boxed{ \rm{ \star{Total \: serface \: area \: of \: the \: cone = 1,244.57m}}}}$

More informations:-

$\sf{Curved \: serface \: area \: of \: a \: cone = \bold {\pi rl}}$

$\sf{Volume \: of \: a \: cone = \bold{ \pi \: {r}^{2} \frac{h}{3} }}$

❖ Hope this helps you!