Finding Area & Volume

Report
Triangles, Quadrilaterals, Nets,
Prisms & Composite Polygons
PARALLELOGRAM
A=bxh
TRIANGLE
A=bxh
2
TRAPEZOID
1) add the top & bottom bases
2) multiply the sum by height
3) divide by 2
A = (b1 + b2) x h
2
Area = b x h
2
5 cm x 8 cm = 40 cm2 = 20 cm2
2
2
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4in
Area = b x h
2
6 cm x 6 cm = 36 cm2 = 18 cm2
2
2
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Area = b x h
10 cm x 5 cm = 50 cm2 = 25 cm2
2
2
2
A=bxh
10.3 cm x 6.2 cm = 63.86 cm2
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A=bxh
10 cm x 3 cm = 30 cm2
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A=bxh
8 cm x 6 cm = 48 cm2
 A = (b1 + b2) x h

2
1) 4 ft + 6 ft = 10 ft
2) 10 ft x 2 ft = 20 ft2
3) 20 ft2 ÷ 2 = 10 ft2
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A = (b1 + b2) x h
2
1) 2 ft + 4 ft = 6 ft
2) 6 ft x 5 ft = 30 ft2
3) 30 ft2 ÷ 2 = 15 ft2
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A = (b1 + b2) x h
2
1) 7 ft + 8 ft = 15 ft
2) 15 ft x 4 ft = 60 ft2
3) 60 ft2 ÷ 2 = 30 ft2
A Composite Polygon is an irregular polygon
made up of different polygons.
To find the AREA OF A COMPOSITE POLYGON,
first break the polygon into simpler parts.
This shape breaks down
into these two shapes.
So… find the area of each of the two areas
separately and add the areas together.
Part A
Part B
Area of Part A: 1.7 cm x 4.9 cm = 8.33 cm2
Area of Part B: 2.1 cm x 1.3 cm = 2.73 cm2
The Composite Polygon’s Area is the total of the two parts:
8.33 cm2 + 2.73 cm2 = 11.06 cm2
Total Surface Area
Find the area of each shape separately,
then add the areas together.
1
4 6 2 5
3
AREA OF RECTANGLE 1: 3 CM X 2 CM = 6 CM2
AREA OF RECTANGLE 2: 6 CM X 2 CM = 12 CM2
AREA OF RECTANGLE 3: 3 CM X 2 CM = 6 CM2
AREA OF RECTANGLE 4: 6 CM X 2 CM = 12 CM2
AREA OF RECTANGLE 5: 3 CM X 6 CM = 18 CM2
AREA OF RECTANGLE 6: 3 CM X 6 CM = 18 CM2
TOTAL SURFACE AREA: 6 + 12 + 6 + 12 + 18 + 18 = 96 CM2
Area of Base x Height of Prism
Height of Prism
The triangle is the
BASE of the Prism
1) Identify the shape of the base:
Triangle
2) What is the formula for area for that shape:
(b x h) / 2
3) What is the area of the base:
(7 x 8) / 2 = 56/2 = 28
4) What is the height of the prism:
13
5) What is the formula for volume:
area of base x height of prism
6) What is the volume of the prism:
28 x 13 = 364
Identify the shape of the base:
Square
2) What is the formula for area for that shape:
bxh
3) What is the area of the base:
3 cm x 5 cm = 15 cm2
4) What is the height of the prism:
4 cm
5) What is the formula for volume:
area of base x height of prism
6) What is the volume of the prism:
15 cm2 x 4 cm = 60 cm3

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