Answer:
Step-by-step explanation:
I'm guessing you want the volume?
so for a triangle it's 1/2 base * height for the area
1/2 * 8 * 3 = 12
12*20=240 m^3
[tex]\Large \boxed{\sf 384 \ m^2}[/tex]
Surface area ⇒ area of 2 triangles + area of 3 rectangles
[tex](8 \times 3 \times 0.5 \times 2)+(20 \times 5 \times 2+20 \times 8)=384[/tex]
