If you make a coordinate grid like the one I made, you count the units on the side and on the top/ length and width which gives you 14 as you can see in the picture. The second one is easy. You do 9 x 14 because 8 is width like 14. The third one you multiply the measurements to get the area. Then subtract them. Like (4 x 3) - (4 x 4.2) then subtract the area. Hope this helps!