### Finding Area & Volume

```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
__________________________________________________
4in
Area = b x h
2
6 cm x 6 cm = 36 cm2 = 18 cm2
2
2
__________________________________________________
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
_________________________________
A=bxh
10 cm x 3 cm = 30 cm2
_________________________________
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
_____________________________________________
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
_____________________________________________
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
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,
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
```