The HCF (Highest Common Factor) of three numbers can be found using prime factorization or continued division method. Let's find the HCF of 18, 27, and 36 using both methods.

Using Prime Factorization Method:
1. Prime factorize each number:
- 18 can be written as 2 × 3^2
- 27 can be written as 3^3
- 36 can be written as 2^2 × 3^2

2. Identify the common prime factors:
- The common prime factors are 2 and 3.

3. Multiply the common prime factors:
- The product of the common prime factors is 2 × 3 = 6.

Therefore, the HCF of 18, 27, and 36 is 6.

Using Continued Division Method:
1. Arrange the numbers in a vertical column:
- 18
- 27
- 36

2. Divide the numbers by any common prime factor starting from the smallest prime number, which is 2 in this case:
- Divide 18 by 2: 18 ÷ 2 = 9
- Divide 27 by 2: 27 ÷ 2 = 13.5 (not divisible by 2)
- Divide 36 by 2: 36 ÷ 2 = 18

3. Repeat step 2 with the new set of numbers:
- Divide 9 by 2: 9 ÷ 2 = 4.5 (not divisible by 2)
- Divide 27 by 3: 27 ÷ 3 = 9
- Divide 18 by 3: 18 ÷ 3 = 6

4. Repeat step 3 until there are no more common factors:
- Divide 9 by 3: 9 ÷ 3 = 3
- Divide 6 by 2: 6 ÷ 2 = 3

5. The last common factor obtained is the HCF:
- The last common factor is 3.

Therefore, the HCF of 18, 27, and 36 is 3.

In conclusion, both the prime factorization method and the continued division method yield the same result. The HCF of 18, 27, and 36 is 6.