Answer:
T.A = 54 + 9/2 √3
Step-by-step explanation:
∵ The figure is triangular prism
∴ T.A = perimeter of the base × height + 2 × area of the base
∵ The base is an equilateral Δ with side length 3"
∴ The perimeter of the base = 3 × 3 = 9 inches
∴ The area of the base = 1/4 S² √3 = 1/4 (3)²√3 = 9/4 √3 inches²
∵ The length of the height of the prism = 6"
∴ T.A = 9 × 6 + 2 × 9/4 √3 = 54 + 9/2 √3
∴ T.A = 54 + 9/2 √3 inches²
Cost price of the manufacturer = 2500×100/120 = 2083.33 dollars
The parabola opens downward
