Given:
a = 4
b = 5
c = unknown
Let's find the length of c.
Here, we are given a right triangle, where c is the longest side.
The longest side of a right triangle is called the hypotenuse.
To find the hypotenuse, apply Pythagorean Theorem:

Input values into the equation above:

Take the square root of both sides:
![\begin{gathered} \sqrt[]{c^2}=\sqrt[]{41} \\ \\ c=6.4 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/apxqb982mmj82dd7hclnq7cjg14ytm0qi1.png)
Therefore, the length of the missing side, c =