a. The figure is a triangular pyramid. You can findits surface area by adding up the area of the three faces of the triangle and the area of the base. A derived formula also is used where the SA is equal to 12 times the perimeter of base times the slant height, added to that is the area of the base. The area of the square base is s^2. Its perimeter is 4s. SA of Pyramid = 12*P*l + s^2 SA of Pyramid = 12*4s*l + 16^2 SA of Pyramid = 12*4(16)*(17) + (16)^2 SA of Pyramid = 11,008 square inches b.) The formula for the SA of a cone is: SA of cone = πr[r+√(h^2+r^2)] SA of cone = π(3)[(3+√(8^2+3^2)] SA of cone = 108.8 square inches
13. Find the surface area of each figure to the nearest tenth. Show your work.