As per the question,

The shape of the well will be cylindrical

Depth (h) of well = 20 m

Radius (r) of circular end of well =

Area of platform = Length × Breadth = 22 × 14 m²

Let height of the platform = H

Volume of soil dug from the well would be equal to the volume of soil that is scattered on the platform.

Volume of soil from well = Volume of soil used to make such platform

πr²h = Area * Height

π * ()² * 20 = 22 * 14 * H

H = * *

= 2.5 m

Hence, the height of the platform = 2.5m