Answer:
[tex]\large\boxed{S.A.=96\ cm^2}[/tex]
Step-by-step explanation:
We have:
(1) two trapezoids with bases b₁ = 7cm and b₂ = 5cm and the height h = 4cm
(2) three rectangles 3 cm × 7 cm, 3 cm × 4 cm and 3 cm × 5 cm.
The formula of an area of a trapezoid:
[tex]A=\dfrac{b_1+b_2}{2}\cdot h[/tex]
Substitute:
[tex]A=\dfrac{7+5}{2}\cdot4=24\ cm^2[/tex]
Calculate the areas of the rectangles:
[tex]A_1=(3)(7)=21\ cm^2\\\\A_2=(3)(4)=12\ cm^2\\\\A_3=(3)(5)=15\ cm^2[/tex]
The Surface Area:
[tex]S.A.=(2)(24)+21+12+15=96\ cm^2[/tex]
