7th Grade Math

590 Volume and Surface Area

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Example 1 Find the surface area of each cylinder. Round to the nearest tenth.

4.

10 yd

6 yd 5. 12.5 m

9 m

6.

18 ft

3 ft

7.

5.6 mm

8.7 mm

8. 5 cm

6.2 cm

9.

4 in.

11 in.^12

Example 2 10. CANDLES A cylindrical candle has a diameter of 4 inches and a height of

7 inches. To the nearest tenth, what is the surface area of the candle?

11. PENCILS Find the surface area of an unsharpened cylindrical pencil that
    has a radius of 0.5 centimeter and a height of 19 centimeters. Round to
    the nearest tenth.

ESTIMATION Estimate the surface area of each cylinder.

B 12. 13.

3.7 m

8.2 m 14.

6.5 ft

12.8 ft

2.2 cm

4.8 cm

1515 PACKAGING The mail tube shown is

made of cardboard and has plastic end

15 in.

2.5 in.

caps. Approximately what percent of

the surface area of the mail tube is

cardboard?

C 16. CHALLENGE If the height of a cylinder is doubled, will its surface area

also double? Explain your reasoning.

17. E WRITE MATH Suppose you are simplifying an expression involving
    π. Will it make a difference if you round π to 3.14 or use the pi key on
    your calculator? Justify your reasoning.


18. REASONING Which has a greater surface area: a cylinder with radius
    6 centimeters and height 3 centimeters or a cylinder with radius
    3 centimeters and height 6 centimeters? Explain your reasoning.

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