Question

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

Answer 1

Step-by-step explanation

The surface area of a cylinder is given by:

`A=2\pi r* h+2\pi r^2=2\pi r*(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*6cm*(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*4cm^*(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*2cm*(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*7cm*(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.