Question

The C.S.A of a cylinder is 792 Sq. cm find its height if its radius is 7cm​

Answer 1

➸ $\underline{\bf{GIVEN}}$

CSA of cylinder is 792cm² and it's radius is 7cm.

➸ $\underline{\bf{TO \: FIND}}$

Height of cylinder.

➸ $\underline{\bf{SOLUTION}}$

Let the height of cyliner be considered as h.

$\longmapsto\sf \: CSA \: of \: cylinder = 2\pi \: rh \\ \\ \longmapsto\sf 792 = 2 \times \frac{22}{7} \times 7 \times h \\ \\ \longmapsto\sf 792= 44 \times h \\ \\ \longmapsto\sf h = \frac{ \cancel{792}}{ \cancel{44} } \\ \\ \longmapsto \sf \ \boxed{ \boxed{ \bf \: \purple{h = 18}}}$

Therefore, height of cylinder is 18cm.

$\\ \\ \sf\bullet \: \underline{\red{ Extra \: Formulas }}$

• Volume of cylinder = πr²h

• TSA of cylinder = 2πrh + 2πr²

• Volume of cone = πr²h/3

• CSA of cone = πr√[h²+r²]

• TSA of cone = πr[r+√(h²+r²)

Answer 2

Answer:

✪ Given :-

• The C.S.A of a cylinder is 792 sq.cm and the radius of a cylinder is 7 cm.

✪ To Find :-

• What is the value of height of a cylinder.

✪ Formula Used :-

$\boxed{\bold{\small{✯\: Curved\: Surface\: Area\: of\: a\: Cylinder\: =\: 2πrh}}}$

✪ Solution :-

» Let, the height be h

➣ According to the question by using the formula we get,

↦ 729 = 2 × $\dfrac{22}{7}$ × 7 × h

↦ 729 = 44 × h

↦ h = $\sf\dfrac{\cancel{729}}{\cancel{44}}$

➥ h = 18 cm

$\therefore$ The height of a cylinder is $\large{\green{\bold{\underline{18\: cm}}}}$

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