At a point A, 20

The above diagram represents the problem in which C is the position of the cloud and D is the position of cloud's shadow.

Let AB = x

Let BC = h

As cloud is at a height of (20 + h) m from the water level. Its shadow will be (20 + h)m deep in the water.

So we have

BD = 20 + (20 + h) = (40 + h) mimpl

Now in △ABC

In △ABD

3h = h + 40

h = 20 m

Distance of point A from Cloud C = AC

By phythagoras theorm in triangle ABC

(AC)² = (AB)² + (BC)²

Implies AC = 40 m