If your question is, "how much had Mr. Kork paid for the car?"
(8,400-200)/.4=$20,500
This would be a great question to just plug into a calculator. I'm sure you will find the answer quite easily if you use a calculator.
for all of them its base times height
v=bh
1) (8*6/2)*9.5=228
2) (4.5/2)^2 *8= 40.5
3) (3.3* 8.3/2) *5.4= 74.0
4) ((3.2+4.8)/2)* 2.7 *4.4= 47.5
