Question

The length of cinema hall is 20m and it's width is 16cm.The sum of areas of its floor and flat root is equal to the surface area of its four walls. Find the volume and height of wall.

Answer 1

Answer:

height = 80/9 (or) 8.88m

volume = 2841.6 m³

Step-by-step explanation:

Given:

Length of cinema hall = 20m.

Width of cinema hall = 16m.

(i)

We know that Area of floor = length * breadth

                                             = 20 * 16

                                             = 320 m²

(ii)

Area of flat root = l * b

                          = 20 * 16

                          = 320 m²

Given that Sum of areas of its floor and flat root = surface area of 4 walls

⇒ 320 + 320 = 2(l + b) * h

⇒ 640 = 2(20 + 16) * h

⇒ 640 = h * 72

⇒ h = 640/72 (or) 80/9

⇒ h = 8.88 m.

We know that volume = l * b * h

⇒ 20 * 16 * 8.88

⇒ 2841.6 m³

Hope it helps!