We are given the right-angle triangle with two known sides and one unknown side.
We can use the Pythagoras theorem to find the length of the unknown side.
Recall that Pythagoras theorem is given by

Where c is the side opposite to the 90° angle.
Let us substitute the given values into the above equation

Simplify the equation

Take the square root on both sides
![\begin{gathered} \sqrt[]{a^2}=\sqrt[]{144} \\ a=12 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/8kduu1wtkflo7ce06dtqnoh16xytnoes60.png)
Therefore, the length of the third side of the right angle tri