Question

Work out the surface area of this cylinder. 12 cm radius 35 cm height

Answer 1

Answer:

The surface area of this cylinder is 3545$\frac{1}{7}$ cm²

Step-by-step explanation:

The formula of the surface area of the cylinder is

• Surface area = later area + 2 base area, where

• Lateral area = perimeter of the base × height of the cylinder

Let us use the rules above to solve the question

∵ The base of the cylinder is a circle

∵ The perimeter of the circle = 2 π r

∵ The radius of the cylinder is 12 cm

∴ r = 12

∴ The perimeter of the base = 2 (12) (π)

∴ The perimeter of the base = 24π cm

∵ The height of the cylinder is 35 cm

∴ h = 35 cm

→ By using the rule of the lateral area above

∵ The lateral area = 24π × 35

∵ π = $\frac{22}{7}$

∴ The lateral area = 24 × $\frac{22}{7}$ × 35

∴ The lateral area = 2640 cm²

∵ The area of the circle = π r²

∴ The area of the base = $\frac{22}{7}$ × (12)² = $\frac{22}{7}$ (144) = 452$\frac{4}{7}$ cm²

→ By using the rule of the surface area above

∴ The surface area = 2640 + 2(452$\frac{4}{7}$) = 3545$\frac{1}{7}$ cm²

∴ The surface area of this cylinder is 3545$\frac{1}{7}$ cm²