Question

Select all the correct cylinders.Which cylinders have a surface area of approximately 528 square units?

Answer 1

Explanation

The surface area of a cylinder is given by:

$A=2\pi r\times h+2\pi r^2=2\pi r\times(r+h).$

Where r is the radius and h is the height of the cylinder.

Cylinder 1

This cylinder has:

• d = 12 cm → r = 12 cm/2 = 6 cm,

,

• h = 8 cm.

Replacing these values in the formula above, we get:

$A_1=2\pi\times6cm\times(6cm+8cm)\cong528\text{ }cm^2.$

Cylinder 2

This cylinder has:

• d = 8 cm → r = 8 cm/2 = 4 cm,

,

• h = 17 cm.

Replacing these values in the formula above, we get:

$A_2=2\pi\times4cm^\times(4cm+17cm)\cong528\text{ }cm^2.$

Cylinder 3

This cylinder has:

• r = 2 cm

,

• h = 12 cm.

Replacing these values in the formula above, we get:

$A_3=2\pi\times2cm\times(2cm+12cm)\cong176cm^2.$

Cylinder 4

This cylinder has:

• r = 7 cm,

,

• h = 5 cm.

Replacing these values in the formula above, we get:

$A_1=2\pi\times7cm\times(7cm+5cm)\cong528\text{ }cm^2.$

We see that cylinders 1, 2 and 4 have an area of approximately 528 cm².

Answer

Cylinders 1, 2 and 4.