<span>When the product of two numbers is one</span>
as you already know, the area of a rectangle is just length*width, so is just the product of those two.

There is a mistake 9,12,13 is not a right triangle. but 9,12,15 is. IF you use this triangle instead, then the area of the 13,14,15 triangle is the sum of the area of the other two triangles.
Yes he will
Because math is cool
Let books =x and games =y
2x+2y=26
4x+1y=28
If you solve for x and y, x=5 and y=8