The area of the base and top is given by:
A1 = (1/2) * (9) * (12)
A1 = 54 cm ^ 2
Then, we have three rectangles:
rectangle 1:
A2 = (15) * (20)
A2 = 300 cm ^ 2
rectangle 2:
A3 = (12) * (20)
A3 = 240 cm ^ 2
rectangle 3:
A4 = (9) * (20)
A4 = 180 cm ^ 2
The surface area will be:
A = 2A1 + A2 + A3 + A4
A = 2 * (54) + 300 + 240 + 180
A = 828 cm ^ 2
Answer:
The surface area of a rectangular prism is:
A = 828 cm ^ 2