See image attached for the illustration
We could find the length of the unknown side using pythagorean theorem. The square of hypotenuse is equal to the sum of the squares of the other two sides.
h² = 5² + 5²
h² = 25 + 25
h² = 25 × 2
h =
![√(25 * 2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/jbg3tcw3elpvbbs8qypqh9xp1k1qs265mt.png)
h = √25 × √2
h = 5 × √2
h = 5 × 1.414
h = 7.07
to the nearest whole number h = 7
The length of unknown hypotenuse is 7 inches