For the first problem, add the areas of the three triangles to find the area of the polygon.
A = 31.8 u^2 + 39.2 u^2 + 35.5 u^2 = 106.5^2
For the second problem, you can divide the entire polygon into many smaller rectangles and add their areas, but there is a faster way. Find the area of the outer rectangle, and subtract the areas of the two 3 in. by 4 in. rectangles.
A = A(outer rectangle) - A(two smaller rectangles)
A = 10 in. * 5 in. - 2(3 in. * 4 in.)
A = 50 in.^2 - 24 in.^2
A = 26 in.^2
