Square root of 81/144

It's square root of 81 = 9

over square root of 144 = 12

So 9/12 = 3/4

I see that the numerator and the denominator are both squared numbers.

81 is the same as 9^2 - so the square root of it is 9.

144 has a sq rt of 12

9/12 would be the sq rt of 81/144