Answer:
The number that goes beneath the radical is
.
Explanation:
If you are dealing with any right triangle with
given sides, using the Pythagorean Theorem, as shown below, makes things relatively simple.
- Pythagorean Theorem:

and
are both the smaller sides of the triangle, while
is the hypotenuse (the longest side of the triangle).
In this case, we have 4 equivalent right triangles with given sides
and
for the hypotenuse, so let's see what we need to solve for by writing down what we know in a form following the Pythagorean Theorem.
Equation:

Given:

?

Work:

- Isolate the unknown value without plugging in our known values yet. This step is unnecessary, but can help if you have trouble with making mistakes with your algebra.

- Plug in our given values and solve for
.

The number that goes beneath the radical is
.