If a rectangular piece of cloth measuring 20 inches by 10 inches is cut into exactly two squares, each of which are then cut into exactly two triangles, what is the area of one of the triangles, in square inches?


A. 20

B. 40

C. 50

D. 60

E. 80

If the textbook approach is simple and apparent, just use it. In this case, if the rectangle is to be cut into two squares it must be split equally in half.

Using the area formula for rectangles: l x w = area, we find the rectangle area is 10 x 20 = 200. Thus, each square area = 200/2 = 100.

Finally, each triangle will be half of a square. Thus each triangle area = 100/2 = 50. Select Choice C.