Respuesta :

Total amount of cardboard the designer will need is 62.5 square feet.

Solution:

Side length of the base = 5 ft

Area of the base = Side × Side

                            = 5 ft × 5 ft

Area of the base = 25 ft²

Area of a triangle  [tex]=\frac{1}{2} \times5\times\frac{15}{4}[/tex]

                            = 9.375 ft²

Area of 4 triangle = 4 × 9.375

                             = 37.5 ft²

Total area of the shape = Area of the base + Area of 4 triangle

                                       = 25 + 37.5

                                       = 62.5 ft²

Total amount of cardboard the designer will need is 62.5 square feet.