Hi, I am rather new to Solidworks and am trying to create a floor that goes down lower at the drain area.

I have created a 3d sketch of bottom of the floor, and would like to make it 10mm thick.

Did I approach this wrong or how should I do it?

Drain is the square area in the middle, it is 5mm lower than the highest points of the floor (outside edge and flat side on the right).

Any help would be appreciated

Pieter