Question

4. Find the total surface area of a right circular cylinder whose radius is equal to 7
m and height is equal to 21 m.
​

Answer 1

• Total surface area (T.S.A.) of a cylinder = 1232 m²

Given :–

• Radius of a right circular cylinder = 7 m.
• Height of a right circular cylinder = 21 m.

To Find :–

• The total surface area of a right circular cylinder.

Solution :–

We know that,

Total surface area of a cylinder (T.S.A.) = $\sf 2\pi r(r + h)$

We have,

• Radius = r = 7 m.
• Height = h = 21 m.

We know that,

• Value of $\sf \pi = \dfrac{22}{7}$

Now, substitute all the values in the formula of the total surface area of a cylinder.

$\hookrightarrow 2 \times \dfrac{22}{ \cancel7} \times \cancel7 \: m(7 \: m+ 21 \: m)$

$\hookrightarrow 2 \times \dfrac{22}{1} \times 1 \: m(28 \: m)$

$\hookrightarrow 2 \times 22 \: m \times 28 \: m$

$\hookrightarrow 44 \: m \times 28 \: m$

$\hookrightarrow 1232 \: {m}^{2}$

Hence,

The total surface area (T.S.A.) of a cylinder = 1232 m².