Write down the first measurement. For instance, you might have leg of a triangle that is 8 inches long.
Write a division symbol or a colon (/ or :).
Write the second measurement. In this example, you might be comparing the first leg of the triangle to another leg that is 4 inches long. Therefore, you would write 8/4 or 8:4.
Divide the first measurement by the second. In this case, you would divide 8 by 4 to get 2. This means that the first leg is twice as long as the second.