Answer:
816 cm²
Step-by-step explanation:
Surface area of the composite figure = (surface area of the larger rectangular prism + surface area of the smaller rectangular prism) - area of the side of the smaller rectangular prism that is joined to the bigger prism.
✔️Surface area of the larger rectangular prism:
Area = L*W*H = 20*5*6 = 600 cm²
✔️surface area of the smaller rectangular prism:
Area = L*W*H = 12*4*6 = 288 cm²
✔️area of the side of the smaller rectangular prism that is joined to the bigger prism.
Area = L*W = 12*6 = 72 cm²
Surface area of the composite = (600 + 288) - 72 = 888 - 72 = 816 cm².
