The wattage would have to support everything you're running at one time. So the wattage has to be greater than or at least equal to the sum of the watts used. I added what was running and my final answer is...
When you're dividing by a negative number
Distributive property
this ia the answer
A=1/2 × (a+b) × h
=1/2 × (45+37) × 6
=1/2 × 82 × 6
=246mm^2
I hope this helps.