Alex has a grid in the shape of a rectangle. he has right triangles. each right triangle has an area of 25 square millimeters and each right triangle fits on the grid. if the length of the grid is 20 centimeters and the width is 12 centimeters, how many right triangles can alex fit on the grid?

First you have to find the area of the rectangular grid. The area of a rectangle is length•width.
So:
A= 20•12
A= 240cm
Then you need to convert 240cm into mm.
240cm is 2400mm.

Then you need to figure out how many triangles can fit into the rectangle if all the triangles have an area of 25mm. So you divide 2400 by 25.
2400:25= 96

So Alex can fit 96 triangles into the grid.