ANSWER
[tex]282.7ft^2[/tex]
EXPLANATION
Recall, the formula for calculating the surface area of a cone is;
[tex]A=\pi r^2+\pi r\sqrt{r^2+h^2}[/tex]
Given;
[tex]\begin{gathered} radius(r)=5 \\ height(h)=12 \end{gathered}[/tex]
Substitute the values into the formula;
[tex]\begin{gathered} A=\pi 5^2+\pi 5\sqrt{5^2+12^2} \\ =\pi5^2+\pi5\sqrt{25+144} \\ =25\pi+5\pi\times13 \\ =25\pi+65\pi \\ =90\pi \\ =90\times3.14 \\ =282.74 \\ \cong282.7 \end{gathered}[/tex]
