7th Grade Math

Chapter Study Guide and Review

614 Volume and Surface Area

Surface Area

Surface Area of Prisms (Lesson 2B)

Find the surface area of each rectangular

prism. Round to the nearest tenth if

necessary.

23.

7 yd

3 yd 8 yd

24.

7.6 m

12 m

8.9 m

25. MOVING A large wardrobe box is
    2.25 feet long, 2 feet wide, and 4 feet
    tall. How much cardboard was needed
    to make the box?

EXAMPLE 5 Find the surface area of the

rectangular prism.

8 cm

3 cm 10 cm

Surface area of rectangular prism

= 2 h + 2 w + 2 hw

= 2 (10)(8) + 2 (10)(3) + 2 (8)(3) or 268

The surface area is 268 square centimeters.

Surface Area of Cylinders (Lesson 2C)

Find the surface area of each cylinder.

Round to the nearest tenth.

26.

13 mm

4 mm

27.

24 in.

18 in.

28. DESIGN A can of black beans is 5 _^12 inches
    high, and its base has a radius of 2 inches.
    How much paper is needed to make the
    label on the can? Round to the nearest
    tenth.

EXAMPLE 6 Find the surface area of the

cylinder. Round to the nearest tenth.

8 ft

2 ft

Surface area of cylinder

= 2 πr^2 + 2 πrh

= 2 π(2)^2 + 2 π(2) 8 or 125.7

The surface area is about 125.7 square feet.

Surface Area of Pyramids (Lesson 2E)

Find the surface area of each pyramid.

Round to the nearest tenth.

6 in.

11 in.

6 in.^

5.1 m

5.1 m

9 m

" = 11.3 m^2

EXAMPLE 7 Find the surface area of the

pyramid. Round to the nearest tenth.

Surface area of pyramid

5 m

5 m

= B + _^1 7 m

2 P

= 25 + _^12 (20)(7) or 95

The surface area is

95 square meters.

Lesson 2

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