8. Problem 1 SOLUTION Using a Net to Find Surface Area You can use a net to find the area of the toy chest as shown above. Add the area of all the faces of the net. The surface area of the storage chest is 2250 square inches.
9. Problem 2 Finding the Surface Area of a Cylinder SOLUTION The radius is one half the diameter, so r = 4 cm . S = 2 π r 2 + 2 π r h = 2 π ( 4 ) 2 + 2 π ( 4 )( 10.7 ) ≈ 369.264 Write formula for surface area. Substitute 3.14 for π, 4 for r and 10 . 7 for h . ANSWER The surface area of the can is 369.264 square centimeters.
10. Problem 3 Find the surface area. The area of each side face is 5 ft · 3 ft = 15 ft 2 The area of the front and back faces is 3 ft · 12 ft = 36 ft 2 The area of the bottom and top faces is 5 ft · 12 ft = 60 ft 2 The surface area is 15 ft 2 + 36 ft 2 + 60 ft 2 x 2 = 222 ft 2
11. Problem 4 Find the surface area of the net . ANSWER The area of each triangle is 6 m · 8 m = 24 m 2 The area of the large rectangle is 10 m · 14 m = 140 m 2 The area of the small rectangle is 6 m · 14 m = 84 m 2 The area of the middle rectangle is 8 m · 14 m = 112 m 2 The total surface area is ( 2 · 24 m 2 ) + 140 m 2 + 84 m 2 + 112 m 2 = 384 m 2 1 2
12. Problem 5 The area of each circular base is 8 2 π = 200.96 in. 2 The area of the rectangle is 20 in. · 16 π in. = 1004.8 in 2 The total area is 2 · 200.96 in. 2 + 1004.8 in. 2 = 1406.7 ft 2 Find the surface area of the net ANSWER
