Question

Find the unknown side length, x. Write your answer in simplest radical form.

Answer 1

Correct option: D

Explanation:

In the figure we have a right triangle, that is, one of the angles is a 90° angle. Therefore, we can use the Pythagoras' theorem to find the relation between the sides of the triangle:

`a^2 = b^2 + c^2`

Where b and c are cathetus of the triangle (sides adjacent to the 90° angle) and a is the hypotenuse (opposite side to the 90° angle).

So in our case, we have that x is the hypotenuse, and 40 and 42 are cathetus, so we have:

`x^2 = 40^2 + 42^2`

`x^2 = 1600 + 1764`

`x^2 = 3364`

`x = 58`

So the correct option is D.