Question

Q12. The ends of a cylinder have radii of 18cm. If its lateral surface area is 7920 sq cm, find its height *​

Answer 1

Answer:

Right cylinder

Solve for height

h≈70.03cm

r Radius

18

cm

AL Lateral surface

7920

cm²

Using the formula

AL=2πrh

Solving forh

h=AL

2πr=7920

2·π·18≈70.02817cm

Answer 2

Given:

The ends of a cylinder have radii of 18cm.

To Find:

If its lateral surface area is 7920 sq cm, find its height

Solution:

A cylinder is a 3-D figure which looks like when a circle is elongated on the z-axis( being the height) so it forms two bases which are circles and a distance between these bases is the height of the cylinder.

The lateral surface area (LSA) can be found by using the formula as,

$LSA=(2\pi r)*h$

where 2pi r is the circumference of the base and 'h' is the height of the cylinder,

It is given that the bases have a radius of 18cm then the circumference will be,

$C=2\pi r\\=36\pi cm$

Now we are given the lateral surface area as 7920cm^2 and we need to find the height we have,

$7920=36\pi*h\\h=70cm$

Hence, the height of the cylinder is 70cm.