9514 1404 393
Answer:
382 cm²
Explanation:
The side facing is a trapezoid with bases 8 and 14 cm, and height 7 cm. Its area is ...
A = 1/2(b1 +b2)h
A = (1/2)(8 +14)(7) = 77 . . . . cm²
The perimeter of the face is ...
7 cm + 8 cm + 9 cm + 14 cm = 38 cm
The total surface area is the sum of the lateral area and the base area.
SA = LA + BA
SA = (38 cm)(6 cm) + 2×(77 cm²) = 228 cm² + 154 cm²
SA = 382 cm²
The surface area of the composite figure is 382 square centimeters.
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Additional comment
The lateral area is the width of a rectangular face (6 cm) times the total of all of the lengths of those faces. That total is the perimeter of the trapezoidal base (38 cm).
There are two trapezoidal bases that contribute area. The first calculation figured the area of one of them.