Question

the C.S.A. of right circular cone of height 16 cm and base radius 12cm is

Answer 1

Here,

Slant height=20cm

C.S.A=753.16cm

Answer 2

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\therefore{\text{C.S.A\:of\:cone=753.6\:cm}^{2}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{ \underline \bold{Given : }} \\ : \implies \text{Radius(r) =12 \: cm} \\ \\ : \implies \text{Height(h) =16\: cm} \\ \\ \red{ \underline \bold{To \: Find : }} \\ : \implies \text{C.S.A\: of \: cone = ?}$

• According to given question :

$\bold{As \: we \: know \: that} \\ : \implies \text{Slant \: height = hypotenuse \: of \: right \: circular \: cone} \\ \\ : \implies {h}^{2} = {p}^{2} + {b}^{2} \\ \\ :\implies {l}^{2} = {16}^{2} + {12}^{2} \\ \\ : \implies {l}^{2} = 256+ 144 \\ \\ : \implies {l} = \sqrt{400} \\ \\ \green{: \implies {l} = 20\: cm} \\ \\ \bold{As \: we \: know \: that \: C.S.A \: of \: cone}\\ : \implies \text{C.S.A\: of \: cone} = \pi rl \\ \\ : \implies \text{C.S.A \: of \: cone} = \frac{22}{7} \times 12 \times 20 \\ \\ : \implies \text{C.S.A \: of \: cone} =3.14 \times 240\\ \\ \green{ : \implies \text{C.S.A\: of \: cone} =753.6\: {cm}}^{2}$