Question

radius of the base 4.2 cm and height 90cm find the curved surface area and the total surface area of a cylinder whose the dimension of these​

Answer 1

Answer:

TSA = cm^2

CSA = cm^2

Step-by-step explanation:

Curved Surface Area ( CSA )

= 2rrh

= 2 ×22/7 × 4.2 × 90

= 44 × 6 × 9

= 2376 cm^2

Total Surface Area ( TSA )

=2rr(r +h )

= 2 × 22÷7 × 4.2(4.2 + 90 )

= 2× 22 ×0.6 × 94.2

= 44 × 56.52

= 2486.88 cm^2

Answer 2

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

$\green{\therefore{\text{C.S.A\:of\:cylinder=2376\:cm}^{2}}}$

$\green{\therefore{\text{T.S.A\:of\:cylinder=2486.88\:cm}^{2}}}$

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

$\green{ \underline \bold{Given : }} \\ : \implies \text{Radius(r) = 4.2\: cm} \\ \\ : \implies \text{Height(h) = 90 \: cm} \\ \\ \red{ \underline \bold{To \: Find : }} \\ : \implies \text{C.S.A \: of \: cylinder = ? }\\ \\ : \implies \text{T.S.A\: of \: cylinder = ? }$

• According to given question :

$\bold{As \: we \: know \: that } \\ : \implies \text{C.S.A\: of \: cylinder} =2\pi rh \\ \\ : \implies \text{C.S.A\: of \: cylinder} =2 \times \frac{ 22}{7} \times 4.2 \times 90 \\ \\ : \implies \text{C.S.A\: of \: cylinder} =2 \times 22 \times 54 \\ \\ \green{ : \implies \text{C.S.A\: of \: cylinder} =2376 \: {cm}^{2}} \\ \\ \bold{As \: we \: know \: that} \\ : \implies \text{T.S.A\: of \: cylinder} =2\pi r(h + r) \\ \\ : \implies \text{T.S.A\: of \: cylinder} =2 \times \frac{22}{7} \times 4.2(90 + 4.2) \\ \\ : \implies \text{T.S.A\: of \: cylinder} =2 \times 22 \times 56.52 \\ \\ \green{ : \implies \text{T.S.A\: of \: cylinder} =2486.88\: {cm}^{2} }$