You have two triangles at each end and a rectangle in the middle. To solve for the triangles it's b x h divided by 2.... so 3.75 x 3.75 = 7.03 mm squared x 2 ( because there are 2 triangles so 14.06 mm squared now for the rectangle which length is 5.25 x width which is 3.75 so area is 19.69 mm squared now ad them together
14.06 plus 19.69 which is
33.75 mm squared
Hope that helps
