Please help me with question 13. My teacher sayslength= 10hight= 8I don't know how he got those answers.

The figure in the diagram is a square based pyramid
Part A
we recreate the image of one face to get the length
The length can be found using pythagoras theorem.
[tex]\begin{gathered} (2\sqrt[]{34})^2=l^2+\text{ (12/2)}^2 \\ 4\times34=l^2+6^2 \\ 136=l^2+36 \\ l^2=136-36 \\ l^2=100 \\ find\text{ the square root of both sides} \\ l=10ft \end{gathered}[/tex]