Answer: 6.71
Step-by-step explanation: Using the Pythagorean Theorem, we know that a^2 + b^2 = c^2. Substitute a and b with 6 and 3 respectively and we get 6^2 + 3^2 = c^2. Then 36 + 9 = c^2. Next, 45 = c^2, so we take the square root of 45 and round it to the nearest hundredth, giving the answer of 6.71.