Answer:
228cm^2
Explanation:
Formulas we'll use: area of a rectangle is length x width, and area of a triangle = 1/2x base x height
the base is a rectangle, 10 by 3 cm. 10 x 3 = 30cm^2
the sides are also rectangles, 13 by 3 cm. 13 x 3 = 39, but there are 2 of them, 39 x 2 = 78cm^2
The top and bottom are triangles, 1/2(10)(12) = 1/2(120) = 60, but there are 2 of them, 60 x 2 = 120cm^2
Add up the areas to get your total surface area. It's in square cm
30 + 78 + 120 = 228cm^2