1. Triangles, Quadrilaterals, Nets, Prisms & Composite Polygons
Finding Area & Volume

2. Formulas You Need To Know
PARALLELOGRAM
TRIANGLE
A = b x h
A = b x h 2

3. Formulas You Need To Know
TRAPEZOID
1) add the top & bottom bases
2) multiply the sum by height
3) divide by 2
A = (b1 + b2) x h 2

4. Finding Area - Triangles
Area = b x h 5 cm x 8 cm = 40 cm2 = 20 cm __________________________________________________ Area = b x h 6 cm x 6 cm = 36 cm2 = 18 cm Area = b x h 10 cm x 5 cm = 50 cm2 = 25 cm
4in

5. Finding Area - Parallelograms
A = b x h cm x 6.2 cm = cm2
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A = b x h cm x 3 cm = 30 cm2
A = b x h cm x 6 cm = 48 cm2

6. Finding Area - Trapezoids
A = (b1 + b2) x h ) 4 ft + 6 ft = 10 ft
) 10 ft x 2 ft = 20 ft2
3) 20 ft2 ÷ 2 = 10 ft2
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A = (b1 + b2) x h ) 2 ft + 4 ft = 6 ft
) 6 ft x 5 ft = 30 ft2
3) 30 ft2 ÷ 2 = 15 ft2
A = (b1 + b2) x h ) 7 ft + 8 ft = 15 ft
) 15 ft x 4 ft = 60 ft2
3) 60 ft2 ÷ 2 = 30 ft2

7. Composite Polygons
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.

8. Finding Area – Composite Polygon
This shape breaks down into these two shapes.
So… find the area of each of the two areas separately and add the areas together.

9. Find the Area… Area of Part A: 1.7 cm x 4.9 cm = 8.33 cm2
Part B
Area of Part A: cm x 4.9 cm = 8.33 cm2
Area of Part B: cm x 1.3 cm = 2.73 cm2
The Composite Polygon’s Area is the total of the two parts:
8.33 cm cm2 = cm2

10. Net Figures – Total Surface Area
Total Surface Area Find the area of each shape separately, then add the areas together.

11. Finding Total Surface Area1 3 2 4 5 6
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: = 96 CM2

12. FINDING VOLUME

13. You Only Need One Formula
Area of Base x Height of Prism
The triangle is the BASE of the Prism
Height of Prism

14. area of base x height of prism
Follow These Steps…
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

15. Follow These Steps…
Identify the shape of the base: Square 2) What is the formula for area for that shape: b x h 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