7th Grade Math

596 Volume and Surface Area

Examples 1 and 2 Find the total surface area of each pyramid. Round to the nearest tenth.

11

7 in.

5 in. 5 in.

2.

9 m

9 m

9 m

12 m

35.1 m^2

Example 3 3. MONUMENTS The Washington Monument is an obelisk with a square

pyramid top. The slant height of the pyramid is 55.5 feet, and the square

base has sides of 34.5 feet. Find the lateral area of the pyramid.

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

Extra Practice begins on page EP2.

Examples 1 and 2 Find the total surface area of each pyramid. Round to the nearest tenth.

4.

6.4 cm

6.4 cm

6.1 cm

5.

17 mm 17 mm

15 mm

17 mm

" ≈ 125 mm^2

6.

8.2 in.

15.9 in.

8.2 in.

(^)

7. The base of a square pyramid has a side length of 27 centimeters. The
   slant height is 25 centimeters. Find the surface area.


8. A triangular pyramid has a slant height of 0.75 foot. The equilateral
   triangular base has a perimeter of 1.2 feet and an area of 0.6 square foot.
   Find the surface area.


9. A square pyramid has a slant height of 4 ^2
   3
   feet. The base has side lengths
   of 2 ^1
   4
   feet. Find the surface area.

Example 3 10. GEMSTONES The gemstone shown has a base that is a

square pyramid with sides 3.4 inches long. The slant

height of the pyramid is 3.8 inches. Find the surface area

of the gemstone.

1111 BIRDHOUSES Isaac is building a birdhouse for a class

project. The birdhouse is a regular hexagonal pyramid. The base has side

lengths of 3 inches and an area of about 24 square inches. The slant

height is 6 inches. Find the approximate surface area of the birdhouse.

B 12. GEOMETRY A square pyramid has a surface area of 175 square inches.

The square base has side lengths of 5 inches. Find the slant height of

the pyramid.

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