Work out the surface area of this cylinder.

12 cm radius
35 cm height

The surface area of this cylinder is 3545 cm²

Step-by-step explanation:

The formula of the surface area of the cylinder is

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 =

∴ The lateral area = 24 × × 35

∴ The lateral area = 2640 cm²

∵ The area of the circle = π r²

∴ The area of the base = × (12)² = (144) = 452 cm²

→ By using the rule of the surface area above

∴ The surface area = 2640 + 2(452) = 3545 cm²

∴ The surface area of this cylinder is 3545 cm²

i pretty sure it is

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6