You would find the area of the inside and outside shape (pretending that the inside shape was not in the outside shape). then, you would take the area of the outside shape and subtract the area of...
If you can find the perimeter, then you can find the area. Calculate the perimeter. Then times the top sides by the left and right sides (and obviously the bottom!) the there you have it. The area of...
There are many ways to find the area of an odd shape. Usually, you have to break the shape down into shapes that you can calculate the area of, and then add the areas of all of those individual...
The best way would be to break the irregular shape down into several familiar shapes. If you can break down a complex figure into a rectangle and two triangles, for instance, you can use the known...