Yes, the square root of 144 is a rational number.
A rational number is defined as any number that can be expressed as the quotient or fraction of two integers, where the denominator is not zero. In this case, the square root of 144 is 12, because 12 x 12 equals 144.
Since 12 can be expressed as the fraction 12/1, it is indeed a rational number. Therefore, the square root of 144 qualifies as a rational number.