The dimensions of a rectangular solid are 8 cm × 4 cm × 1 cm. What is the length (in cm) of its diagonal?

Correct option is A

Given:

Length = 8 cm

Width = 4 cm

Height = 1 cm

Formula Used:
The length of the diagonal of a rectangular solid is given by the formula:

Diagonal = $$\sqrt{L^2 + W^2 + H^2}$$​

where L is the length, W is the width, and H is the height.

Solution:

Diagonal =$$\sqrt{8^2 + 4^2 + 1^2} = \sqrt{64 + 16 + 1} = \sqrt{81} = 9 \text{ cm}$$​

The length of the diagonal is 9 cm.