In a straight prism, at the base of which lies a rectangle with sides of 6 dm and 12 dm

In a straight prism, at the base of which lies a rectangle with sides of 6 dm and 12 dm, and a height of 8 dm. Find the total surface area of the prism.

The area of the total surface of the prism (straight or inclined) is calculated by the formula: S total = 2 • S main + S side.

1) We need to find Sbase, at the base lies a rectangle, its area: S = a • b. That is, Sbn = 6 • 12 = 72 (dm2).

2) The area of the lateral surface of such a prism is found as follows: Sside = Pon • h. Base perimeter – rectangle perimeter: P = 2 • (a + b). That is, Psc = 2 • (6 + 12) = 36 (dm).
Side = 36 • 8 = 288 (dm2).

3) Total we have: Sful = 2 • Sb + Sbok = 2 • 72 + 288 = 432 (dm2).
Answer: S total = 432 dm2.