Question

Total surface area of a cube is 5400 sq. cm. Find the surface area of all vertical faces of the cube.

Answer 1

Let the edge of the cube be l cm.
Total surface area of the cube = 5400 cm²

∴ 6l² = 5400
⇒ l² = `5400/6` = 900

⇒ l = `sqrt900` = 30 cm

∴ Surface area of all vertical faces of the cube
= 4l² 
= 4 × (30 cm)² 
= 4 × 900 cm² 
= 3600 cm²
Thus, the surface area of all vertical faces of the cube is 3600 cm².