Answer:
B.
![5√(2)](https://img.qammunity.org/2022/formulas/mathematics/college/ydj22ckmh9wvppj11vpw83kpb7tj9d1ggo.png)
Explanation:
Hi there!
Notice how the diagonal splits the square into two right triangles. To find the length of the diagonal, we can use the Pythagorean theorem:
where a and b are the legs of a right triangle and c is the hypotenuse, or the side opposite the right angle.
In this case, a is 5, b is 5 and we're trying to solve for c.
Plug in the known values
![5^2+5^2=c^2\\25+25=c^2\\50=c^2\\c=√(50)](https://img.qammunity.org/2022/formulas/mathematics/high-school/qxijid5unzzbwetprgo0ziz6b4kmr6xb8j.png)
Simplify the radical
![c=√(25*2) \\c=5√(2)](https://img.qammunity.org/2022/formulas/mathematics/high-school/id1wlwwc54pxo97ah239q6wz7x5ndqvv7g.png)
I hope this helps!