Question

Find the total surface area of a closed cylindrical drum if its diameter is 42 cm and height is 45 cm.​

Answer 1

Answer:

The total surface area of a closed cylindrical drum if its diameter is 42 cm and height is 45 cm is  7392 sq cm.

Step-by-step explanation:

Given:

The diameter of closed cylindrical drum = 42 cm

r = 42/2 = 21 cm

and height is 45 cm.​

Find the total surface area of a closed cylindrical drum

Formula: The total surface area of a closed cylindrical drum = 2 πr (r + h)

= 2 × 22/7 × 21 (21 + 45)

= 2 × 22 × 3 (56)

= 44 × 168

= 7392

Thus, the total surface area of the closed cylindrical drum is 7392 sq cm.

Answer 2

Answer:

As a result, a closed cylindrical drum's total surface area is $8712 sq cm$

Step-by-step explanation:

In accordance with the information provided in the question,

Given the data in question  closed cylindrical drum  its diameter is 42 cm

So

$r= \frac{42}{2} \\r=21 cm$

When drum  height is 45 cm.​

We have find the value of total surface area of a closed cylindrical drum

We know that the formula of  total surface area of a closed cylindrical drum = 2 πr (r + h)

put the value of $\pi =\frac{22}{7}$

So,

$2\times \frac{22}{7} \times 21(21+45)\\2\times 22\times 3(66)\\44\times 198\\8712$

As a result, a closed cylindrical drum's total surface area is $8712 sq cm$