# 8.3 – Area, Volume and Surface Area

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8.3 – Area, Volume and Surface Area
Area of Plane Regions Rectangle Square Triangle 3 ft 3 ft 2 ft 6 ft 3 ft 4 ft A = l·w A = s·s = s2 A = ½ l·w A = 6·2 A = 32 A = ½ b·h A = 12 sq ft A = 9 sq ft A = ½ ·4·3 A = 6 sq ft

8.3 – Area, Volume and Surface Area
Area of Plane Regions Triangle Parallelogram Trapezoid 8 cm 2 m 3 yd 9 cm 4 m 7 yd 12 cm A = ½ b·h A = b·h A = ½ (b1 + b2)·h A = ½ ·4·2 A = 7·3 A = ½ (12 + 8)·9 A = 4 sq m A = 21 sq yd A = ½ ·20·9 A = 90 sq cm

8.3 – Area, Volume and Surface Area
Calculate the area of the plane region 24 m 18 m 12 m A = A + A A = 12 · 6 + 18·18 6 m A = 72 + 324 6 m A = 396 sq m 24 – 18 = 6 m 18 – 12 = 6 m

8.3 – Area, Volume and Surface Area
Area of Plane Regions Circle Exact Area Approximate Area A = ·r2 A = 3.14 ·r2 r d Calculate the area Exact Area Approximate Area A = ·r2 A = 3.14 ·r2 r d A = 3.14 ·72 A = ·72 A = 49 sq in A = 3.14 ·49 Diameter = 14 inches A = sq in r = 7 inches

8.3 – Area, Volume and Surface Area
Formulas for Volume and Surface Area

8.3 – Area, Volume and Surface Area
Formulas for Volume and Surface Area

8.3 – Area, Volume and Surface Area
Calculate the volume and surface area of a rectangular box (prism) that is 7 feet long, 3 feet wide and 4 feet high. V = l·w·h SA = 2lw + 2wh + 2hl V = 7·3·4 SA = 2(lw + wh + hl) V = 21·4 SA = 2(7·3 + 3·4 + 4·7) V = 84 cu ft SA = 2( ) SA = 2( ) SA = 2(61) SA = 122 sq ft

8.3 – Area, Volume and Surface Area
Approximate the volume and surface area of a cylinder that has a radius of 5 inches and height of 9 inches. ( ≈ 3.14) V =  · r2 · h SA = 2r2 + 2rh V = 3.14·52·9 SA = 2·3.14·52 + 2·3.14·5·9 SA = 2·3.14·25 + 2·3.14·45 V = 3.14·25·9 SA = 50· ·3.14 V = 3.14·225 SA = 3.14( ) V = 706.5 cu in SA = 3.14(140) SA = 439.6 sq in

8.3 – Area, Volume and Surface Area
Calculate the volume of a square-base pyramid that has a base side measurement of 3 meters and a height of 5.1 meters. V = (1/3)· b2 · h V = (1/3)·32·5.1 V = (1/3)·9·5.1 V = 3·5.1 V = 15.3 m3

8.3 – Area, Volume and Surface Area
Approximate the volume of a cone that has a radius of 4 yards and a height of 6 yards. Round the answer to the nearest tenth of a yard. Use 22/7 as the approximation of . V = (1/3) · r2 · h V = (1/3)(22/7)·42·6 V = (1/3)(22/7)·16·6 V = (22/7)·16·2 V = (22/7)·32 V = 704/7 V = 100.6 cu yd

8.4 – Linear Measurement U. S. Units of Length U. S. Unit Fractions

8.4 – Linear Measurement Conversions Convert 6 feet to inches.
Convert 8 yards to feet.

8.4 – Linear Measurement Conversions
Convert 68 inches to feet and inches. Convert 5 yards 2 feet to feet. 5 yd 2 ft = = 17 ft

8.4 – Linear Measurement Conversions
Add 5 feet 8 inches to 8 feet 11 inches. 5 feet 8 inches 13 feet 0 inches 8 feet 11 inches 1 feet 7 inches 13 feet 19 inches 14 feet 7 inches

8.4 – Linear Measurement Conversions Multiply 4 feet 7 inches by 4.
× 4 2 feet 4 inches 16 feet 28 inches 18 feet 4 inches

8.4 – Linear Measurement Conversions
A carpenter cuts 1 ft 9 in from a board of length 5 ft 8 in. What is the length of the remaining piece. 5 feet 8 inches 1 feet 9 inches 4 20 5 feet 8 inches 1 feet 9 inches 3 feet 11 inches 3 ft 11 in

8.4 – Linear Measurement Metric Units of Length Metric Unit Fractions

8.4 – Linear Measurement Conversions Convert 2.5 m to millimeters.
Convert 3500 m to km.

8.4 – Linear Measurement Conversions Subtract 21 mm from 6.4 cm. 64
2.1 43 4.3 43 mm 4.3 cm

8.4 – Linear Measurement Conversions
Multiply 18.3 cm by 6.2 and convert the answer to meters. 18.3 × 6.2 366 1098 11346 113.46 cm

8.4 – Linear Measurement Conversions
A knitted scarf is currently 0.8 m long. If an additional 45 cm is knitted, how long will the scarf be? 80 0.80 + 45 + 0.45 125 1.25 125 cm 1.25 m