Let's begin by listing out the given information
[tex]\begin{gathered} base(b)=5ft \\ height(h)=8ft \end{gathered}[/tex]
The area of the pyramid is given by the sum of the rectangular base & the 4 triangular faces:
[tex]\begin{gathered} SA=A(RectangularBase)+A(Triangularfaces) \\ SA=b^2^{}+4(\frac{1}{2}\cdot bh) \\ SA=5\cdot5+4(\frac{1}{2}\cdot5\cdot8) \\ SA=25+80=105 \\ SA=105ft^2 \end{gathered}[/tex]
