We have:
4 triangles with the base b = 5ft and the height h = 6ft
4 rectangles with the lenght l = 5ft and the width w = 4ft
1 square with side a = 5ft.
The formula of an area of a riangle:
[tex]A_T=\dfrac{1}{2}bh[/tex]
Substitute:
[tex]A_T=\dfrac{1}{2}(5)(6)=\dfrac{1}{2}(30)=15\ ft^2[/tex]
The formula of an area of a rectangle:
[tex]A_R=lw[/tex]
Substitute:
[tex]A_R=(5)(4)=20\ ft^2[/tex]
The formula of an area of a square:
[tex]A_S=a^2[/tex]
Substitute:
[tex]A_S=5^2=25\ ft^2[/tex]
The Surface Area of composite solid:
[tex]SA=4A_T+4A_R+A_S[/tex]
Substitute:
[tex]SA=4(15)+4(20)+25=60+80+25=165\ ft^2[/tex]
Answer: The Surface Area of the composite solid is 165 ft².
