Answer:
The surface area of the composite solid = 480 square feet
Step-by-step explanation: Given that the rectangular prism is of length of 10 feet, width of 10 feet, and height of 6 feet.
A square pyramid with triangular sides with a height of 7 feet.
The base of the pyramid = width of the rectangular prism.
Pyramid base = 10 feet
A pyramid has 4 triangular faces
Area of a triangle = 1/2bh
Area = 1/2 × 10 ×7 = 35 square feet
Total surface area = 35 × 4 = 140
Rectangular prism has 6 faces
But we will be calculating for 5 faces
Total surface area = 2(10×6) + 2(10×6) + (10×10)
= 120 + 120 + 100
= 340
The surface area of the composite solid = pyramid surface + rectangular prism surface
= 140 + 340
= 480 square feet