The surface area of the pyramid is the sum of the areas of the 4 triangles and the square
The area of the square is found this way
[tex]\begin{gathered} As=l^2 \\ As=5^2=25 \end{gathered}[/tex]
The area of each triangle is found this way
[tex]\begin{gathered} At=\frac{b\cdot h}{2} \\ At=\frac{5\cdot8}{2} \\ At=20 \end{gathered}[/tex]
The total surface area is
[tex]\text{Apyr}=20+20+20+20+25=105[/tex]
The area is 105 in^2. The correct option is B
