Find the amount of cardboard needed to make a box for a single slice of pizza. the box is shoen in the shape of a triangular prism as shown

For this case, what you should do is calculate the surface area of the figure.
 We have then:
 Triangles:
 A1 = (1/2) * (7) * (12)
 A1 = 42 in ^ 2
 Rectangles:
 A2 = (1) * (12.5)
 A2 = 12.5 in ^ 2
 A3 = (1) * (7)
 A3 = 7 in ^ 2
 Finally, the total surface area is:
 A = 2A1 + 2A2 + A3
 Substituting values:
 A = 2 (42) + 2 (12.5) + (7)
 A = 84 + 25 + 7
 A = 116 in ^ 2
 
 the amount of cardboard needed to make a box for a single slice of pizza is:
 A = 116 in ^ 2