Respuesta :

Answer:  

[tex]85in^2[/tex]

Step-by-step explanation:

to find the surface area we need to find the followng areas:  

  • area of the square  
  • area of a triangle and multiply it by 4 (because there are 4 triangles)

And once we have those areas, we add them to find the surface area.

Area of the square:

the formula to find the area of a square is:

[tex]a_{square}=l^2[/tex]

where [tex]l[/tex] is the length of the side: [tex]l=5in[/tex]

thus the area of the square is:

[tex]a_{square}=(5in)^2[/tex]

[tex]a_{square}=25in^2[/tex]

Area of the triangles:

the are of 1 triangle is given by

[tex]a_{triangle} =\frac{b*h}{2}[/tex]

where [tex]b[/tex] is the base of the triangle: [tex]b=5in[/tex] (the base of the triangle is the side of the square)

and [tex]h[/tex] is the height of the triangle: [tex]h=6in[/tex]

thus, the area of 1 triangle is:

[tex]a_{triangle} =\frac{(5in)*(6in)}{2}[/tex]

[tex]a_{triangle} =\frac{30in^2}{2}[/tex]

[tex]a_{triangle} =15in^2[/tex]

the area of the 4 triangles is (we multiply by 4):

[tex]a_{4-triangles}=4(15in^2)[/tex]

[tex]a_{4-triangles}=60in^2[/tex]

finally we add the area of the square and the area of the 4 triangles to find the total surface area:

[tex]Surface=25in^2+60in^2[/tex]

[tex]Surface=85in^2[/tex]