Question #N670

In the figure below, $\triangle ABC$ is a right triangle with right angle at $C$. If $AC=4$ and $BC=3$, what is the length of $AB$?
A. 3
B. 5
C. 7
D. 25

Correct Answer is: B

Since $\triangle ABC$ is a right triangle, we can use the Pythagorean Theorem to find the length of the hypotenuse, $AB$. The Pythagorean Theorem states that in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. Therefore, $AB^2 = AC^2 + BC^2 = 4^2 + 3^2 = 16 + 9 = 25$. Taking the square root of both sides, we find $AB = \sqrt{25} = 5$.