Q:

What is the surface area of the triangular prism? [Not drawn to scale]54 square feet67.5 square feet 81 square feet85.5 square feet

Accepted Solution

A:
Answer:The answer is the thirdThe surface area of prism = 81 ft²Step-by-step explanation:∵ The triangular prism has 5 faces- Two triangles ⇒ bases- 3 rectangles ⇒ side faces* to find the surface area of it, we will find the area of  each face and add them together- Area of bases:∵ The bases are right angle triangles with base 6 ft and height 4.5 ft∵ Area triangle = 1/2 × base × height∴ Area one base = 1/2 × 6 × 4.5 = 13.5 ft²∴ Area two bases = 13.5 × 2 = 27 ft² ⇒ (1)- Area of the first rectangle with dimensions 3 ft and 6 ft∵ Area rectangle = L × W ∴ Area 1st rectangle = 3 × 6 = 18 ft² ⇒ (2)- Area of the second rectangle with dimensions 3 ft and 7.5 ft∴ Area 2nd rectangle = 3 × 7.5 = 22.5 ft² ⇒ (3) - Area of the third rectangle with dimensions 3 ft and 4.5 ft∴ Area 3rd rectangle = 3 × 4.5 = 13.5 ft² ⇒ (4)Add (1) , (2) , (3) and (4)∴ The surface area of prism = 27 + 18 + 22.5 + 13.5 = 81 ft²