A)We have been given →
Hieght of trough = 5m
length of trough = 6m
Breadth of trough = 4m
so , As the top is opened for feeding animals.
Area of base = length× Breadth
= (6×4) m²
= 24 m²
Area of Front and back face = Hieght × length
= (5×6) m²
= 30m²
Area of side faces = hieght × Breadth
= (5×4) m²
= 20 m²
____________________________________
B)Total Surface area of trough will be given by formula - 2(lb+bh+hl)
= 2{(6×4)+(4×5)+(5×6)}
= 2{24+20+30}
= 2×74
= 148 m²
As we have been told top is open , so we will deduct top from Total surface Area to obtain Surface area →
(148-24) m²
(Area of top will be same as base area , that is 24m² as we have solved in A)
= 124m²
Answer→ Surface area of trough is 124m²
___________________________________