Use a prime factor to determine squre root of 225

225 = 3^2 5^2

so, √225 = 3*5 = 15

To determine the square root of 225 using a prime factor, we first need to find the prime factorization of 225.

The prime factors of 225 are 3 and 5.

225 can be expressed as: 3 × 3 × 5 × 5

Now, we can pair up the prime factors in pairs of two (since we're finding the square root). In this case, we have two pairs: (3 × 3) and (5 × 5).

Taking the square root of each pair gives us:

√(3 × 3) = 3

√(5 × 5) = 5

Therefore, the square root of 225 is 3 × 5, which equals 15.