1. Review of Area and Volume
Image from Flickruser toastforbrekkie on Feb 12th, 2009
http://www.flickr.com/photos/toastforbrekkie/3275037811/
2. Area
vs
Volume

Two dimensional space in an object 3. Two-dimensional objects only 4. Square Units 5. Three dimensional space in an object 6. Three-dimensional objects only 7. Cubed Units

8. Area of a Square
A=S2
Area of a square is equal to the side squared
Units: Unit of Side2
S
Ex:
S=2 in
A=S2
A=2*2
A=4in2
Ex:
S=7.4 ft
A=S2
A=7.4*7.4
A=54.76 ft2
S
9. Area of a Rectangle
A=S1*S2
Area of rectangle is equal to Side 1*Side 2
Units=unit of side2
S1
S2
Ex:
S1=3
S2=5
A=S1*S2
A=3*5
A=15 units2
Ex:
S1=15.6 cm
S2=23.1 cm
A=S1*S2
A=15.6*23.1
A=360.36 cm2
10. Area of a Triangle
A=1/2b*h
Area of the triangle equals one half of the base times the height
Units: units of b and h2
h
b
Ex:
b=4
h=3
A=1/2b*h
A=1/2(4)*3
A=6 units2
Ex:
b=5.6ft
h=7.4ft
A=1/2b*h
A=1/2(5.6)*7.4
A=20.72 ft2
11. Area of a Circle
A=r2
Area of a circle is equal to pi (3.14159) times the radius2
Units= units of r2
r
Ex:
r=2
A= r2
A= (2)2
A=12.566 units2
Ex:
r=57.2 cm
A= r2
A= (57.2)2
A=10278.78 cm2
12. Volume of a Cube
V=S3
Volume of a cube is equal to the side cubed
Units= unit of side3
S
S
Ex:
S=3.5 ft
V=S3
V=3.53
V=42.875 ft3
S
Ex:
S=7in
V=S3
V=73
V=343 in3
13. Volume of a Box
V=l*w*h
Volume of a box equals the length times the width times the height
Units= units of l,w,h3
w
l
h
Ex:
l=3
w=7
h=2
V=l*w*h
V=3*7*2
V=42 units3
Ex:
l=2.3
w=4.7
h=3.1
V=l*w*h
V=2.3*4.7*3.1
V=33.511 units3
14. Volume of a Sphere
V=4/3r3
Volume equals four thirds pi (3.14159) times the radius cubed
Units= units of the radius3
r
Ex:
r=4.7 in
V=4/3r3
V=4/3(4.7)3
V= 434.893 in3
Ex:
r=2
V=4/3r3
V=4/3(2)3
V=33.51 units3
15. Volume of a Cylinder
V= r2 h
Volume of a cylinder is equal to pi (3.14159) times the radius squared times the height
Units= units of r,h3
r
h
Ex:
r=1.6
h=3.4
V= r2 h
V= (1.6)2 (3.4)
V=27.344 units3
Ex:
r=3
h=5
V= r2 h
V= (3)2 (5)
V=141.372 units3
16. Volume of a Cone
V=1/3r2 h
Volume of a cone is equal to one third times pi (3.14159) times the radius squared times the height
Units=unit of r,h3
h
r
Ex:
r=4
h=5
V= 1/3r2 h
V= 1/3(4)2 (5)
V=83.776 units3
Ex:
r=3.2
h=7.9
V= 1/3r2 h
V= 1/3(3.2)2 (7.9)
V=84.714 units3
17. The END