Question

If radius and height of a cylinder is 70cm and 1.4cm respectively then surface area of a cylinder.

Answer 1

ANSWER:

Surface area of the Cylinder = 31416 cm²

GIVEN:

• Radius of Cylinder = 70 cm
• Height of Cylinder = 1.4 cm

TO FIND:

• Surface area of the cylinder.

SOLUTION:

Surface area of Cylinder = 2πr(r+h)

Here:

• r = 70 cm
• h = 1.4 cm

Putting these values in the formula we get:

Surface area of Cylinder:

$= 2 \times \dfrac{22}{7} \times 70(70 + 1.4) \\ \\ = \dfrac{44}{7} \times 70 \times 71.4 \\ \\ = 440 \times 71.4 \\ = 31416 \: cm {}^{2}$

Surface area of the Cylinder = 31416 cm²

NOTE:

Some important formulas:

Volume of cube = (Edge)³

Volume of Cuboid = (Length)(Breadth)(Height)

Curved surface area of Cylinder = 2πrh

Total Surface area of sphere = 4πr²

Curved surface area of hemisphere = 2πr²

Total surface area of hemisphere = 3πr²

Where:

=> r = radius.

=> h = height