The draw that describes this situation looks like this:
Drawing this helped us to know that the ladder forms a right triangle with one of the walls of the house.
When we have right triangles we can apply the Pythagoras theorem, from the Pythagoras theorem we can express:

Solving for h, we get:
![\begin{gathered} 13^2-5^2=5^2-5^2+h^2 \\ 13^2-5^2=h^2 \\ h=\sqrt[]{13^2-5^2}=\sqrt[]{169-25}=\sqrt[]{144}=12 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/p6nc7es3cm963zbl7nv2qx1duuxizhtbeu.png)
Then, the ladder reach 12 feet up the side of the house