Question

Total surface area of a cube is 600 sq. cm. So the perimeter of its face is ______.

• A. 30 cm
• B. 40 cm
• C. 60 cm
• D. 70 cm

Answer 1

The correct option is B

40 cm

Surface area of a cube = 6a${}^2$
$\Rightarrow$ 6a${}^2$ = 600
$\Rightarrow$ a = 10 cm

The shape of the face of a cube is square.
$\because$ Perimeter of a square = 4 x side

Thus, perimeter of face of cube = 4 x a
= 4 x 10
= 40 cm