Find the surface area of a rectangular prism the sides of the right triangular base 9 centimeters 12 centimeters and 15 centimeters the height of the prism is 20 centimeters

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
 
 The surface area of a rectangular prism is:
 A = 828 cm ^ 2