Question

The total surface area of a cube is 486 cm². Find its lateral surface area and diagonal of the cube.

Answer 1

Total surface area of cube 

= 6a² =486

^​​​​a² = 486/6 = 81^​

a² ​​​​= 81 

a = 9 cm

Lateral surface area of cube 

= 4a² 

= 4 × 81

= 324 cm²

Diagonal = √3 a

                 = √3 × 9

                 = 9√3 cm​

^​​​​​