How to put the copper area for the several nets in the PCB?

Hi

I am concentrating  on the BLDC motor drives, with three phase supply. After putting the  tracks the specific area on the drive board  is been get heating, so we have to provide that copper area. can any one provide the possible solution for this problem.

So i had tried to put the polygon shapes etc and all, but i can't find the solution for this?

Thanks & Regards

Dhamodharan