Hatch?

I understand the general concept of building a teardrop trailer, however, I'm having trouble understanding how to build the hatch.
Forgive my stupidity but how exactly does one achieve the the curve on the hatch?
I apoligize if this is posted in the wrong section. I'm still finding my way around.
-Brandon
Forgive my stupidity but how exactly does one achieve the the curve on the hatch?

I apoligize if this is posted in the wrong section. I'm still finding my way around.
-Brandon
