7.) Area of a square pyramid is given by A = s^2 + 2sl; where s is the side length of the base and l is the slant height. Area of given pyramid = 4^2 + (2 x 4 x 7) = 16 + 56 = 72 ft^2
8.) Area of the given pyramid is the area of the hexagonal base plus the area of the six slant triangles. Area of hexagonal base = (3sqrt(3))/2 x 10^2 = 150 x 1.732 = 259.8 Area of the 6 traingles = 6(1/2 x 10 x 13) = 6 x 65 = 390 Total surface area of the pyramid = 259.8 + 390 = 649.8 ≈ 650 m^2
9.) Using pythagoras rule, the slant height is sqrt(6^2 + 3.5^2) = sqrt(36 + 12.25) = sqrt(48.25) = 6.9 mm
10.) The surface area of a cone is given by πr^2 + πrl Area = π x 6^2 + π x 6 x 20 = 36π + 120π = 490.1 cm^2
