3/4 = 9/12
You know you have 4 and 12 as your denominators. 4 x ? = 12
It's 3. 4 x 3 = 12 what you do to the bottom you do to the top, you multiplied x' 3
3 x 3 = 9
4 x 3 = 12
So, 3/4 is equal to 9/12
or 9 inches of 12 inches is equal to 3/4 of a foot.
Hope this helps. :)