Question

Find the height of the cylinder whose base are is 180cm^2 and its volume is 1080cm^3?

5cm

7cm

6cm

9cm

​

Answer 1

Given-

• Base area=180cm^2
• Volume=1080cm^3

Concept used-

• Area of base=πr^2
• Volume of cylinder=πr^2h

Solution-

Let the radius of base be r

and height of cylinder be h

$\bf area \: of \: base = \pi {r}^{2} \\ \underline{ \boxed{ \bf \: 180 {cm}^{2} = \pi {r}^{2} }}.....1$

$\bf \: volume \: of \: cylinder = \pi {r}^{2}h \\ \bf 1080 {cm}^{3} = \pi {r}^{2} h$

Put 1st in this equation

$\bf \: 1080 {cm}^{3} = 180 {cm}^{2} \times h \\ \bf \: \frac{1080}{180} = h \\ \bf \underline{ \boxed{ \large \bf \: h = 6 \: }}$

So the answer is (c) h=6cm