Question

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

Answer 1

Answer:

Correct option: D

Step-by-step 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.