Question

Why is that boat and aeroplane has made in the streamland shape?

Answer 1

so that they can move fast in a particular direction

Answer 2

Boats and aeroplanes are the bodies moving in the fluids, like ship in water and aeroplane in the air to reduce the fluid friction. This friction cause the aeroplane down and cause it to consume more fuel. To avoid this, boats and aeroplanes are given a special shape called as streamlined shape.