First you would have to divide the rectangle into half, to form two congruent triangles. Then if you multiply the area of 1 of the triangles, it will give you the area of both triangles, and so the area of the triangle as a whole.
Answer: You would divide the rectangle into half, to form two congruent triangles. When you multiply the area of 1 of the triangles, it gives you the area of both triangles, and so the area of the triangle as a whole.
