Question

The perimeter of a base of a room is in the shape of a rectangular prism is $30m$. The lateral surface area of the room is measured to be $210{\text{m}}^2$. Find the height of the room.

• A. 7 m
• B. 14 m
• C. 3.5 m
• D. 10 m

Answer 1

The correct option is A 7 m

The lateral surface area of rectangular prism is the product of perimeter of the base and the height of prism.

Hence,
The lateral surface area of a rectangular prism = Perimeter of base $\times$ height of the room.

Let the height of the room be h.

Given,
Perimeter of base $=30m$

Lateral surface area of the room $=210{\text{m}}^2$

Perimeter of base $\times$ height of the room $=210{\text{m}}^2$

$30\times h=210$

$h=\frac{210}{30}=7m$

Hence, height of the room is 7 m.
Option (a) is correct.