A lentil – or a discus as it is known in athletics – is to be modelled. 

The lateral surfaces of the discus are to be flattened so that they end in a blunt edge. 

To do this, we use a Boolean intersection of three objects. 

The objects required are two compressed spheres and a cylinder.

Example of modelling a discus

1. Position a compressed sphere.
   
2. Duplicate the sphere positioned under "1" and shift it sideways.
   
3. Position a round cylinder (rotated 90° around the x-axis).
4. Generate a Boolean intersection between all three objects.