QUESTION ON SIMPLE GEOMETRY.....

Assuming that the figure you have drawn has one rectangle and two semicircles, the solution goes like this.

Each of the semicircle  is based on the side of length 10 cm.This becomes the diameter.

So the radius of each is 5 cm.

Hence the area of each semicircle is 25.

So area of both semicircles together is 50.

Let the shortest  distance betwen the semicircles is l.

So, we get that,

the length of the other side of the rectangle is 5+5+l=10+l

So the area of the rectangle =10*(10+l)=100+10l

Now,

 the area of the semicircles + the area of the shaded region =area of the full rctangle=100+10l

So,

 

50+100=100+10l

l=5