can someone please help me find the Answer to the following

First, to find the slant height, we use Pythagorean's Theorem to find the slant height, as the image below shows.
Then,
[tex]\begin{gathered} h^2=10^2+7.5^2 \\ h^2=100+56.25 \\ h=\sqrt[]{156.25} \\ h=12.5ft \end{gathered}[/tex]Now, the surface area formula is
[tex]SA=2bs+b^2[/tex]Where s = 12.5 and b = 15.
[tex]\begin{gathered} SA=2\cdot15\cdot12.5+15^2 \\ SA=375+225 \\ SA=600ft^2 \end{gathered}[/tex]