Length:
kilometer (km) 1 km = 1,000 m 2.5 times around an indoor track
meter (m) 1 meter Meter stick
centimeter (cm) 1 cm = 0.01 meter Thickness of a CD case
millimeter (mm) 1 mm = 0.0001 meter Thickness of a CD
Mass: (Weight)
kilogram (kg) 1 kg = 1,000 grams 4 videocassettes
gram (g) 1 gram Small Paper Clip
milligram (mg) 1 mg = 0.001 gram Mass of an eyelash
Capacity:
kiloleter (kL) 1 kL = 1,000 liters Water in 2 or 3 bathtubs
liter (L) 1 liter A bottle of juice
milliliter (mL) 1 mL = 0.001 liter 2 dewdrops
What would we use to measure:
1. The distance from your house to the school?
2. The length of the white board ?
3. The weight of a car?
4. The weight of a piece of paper?
5. A pea?
6. The capacity of a gas tank?
7. The capacity of a lake?
8. The capacity of a raindrop?
9-3 Perimeter and Areas of Rectangles
The area of a figure is the number of square units the figure contains. You can estimate the area of any figure by using a grid and counting the number of squares it covers.
How many squares are completely filled in?
How many squares are partially filled in?
Add them together, that is the estimated area.
The perimeter of a figure is the distance around the figure.
Formula for perimeter of a rectangle:
P = 2(l +w)
5 cm
3 cm 3 cm
5 cm
P = 2(5+3)
5+3=8 � 8x2 = 16
So, the perimeter of this rectangle is 16 cm.
Formula for area of a rectangle:
A=l x w
A= 5 x 3
5 x 3 = 15
2
So, the area of the rectangle is 15 cm
Formula for area of a square:
P= 4s
2
A= s
2 cm
2 cm 2 cm
2 cm
The perimeter would be 8 cm.
2
The area would be 4 cm
9-4 Areas of Parallelograms and Triangles
Area of a Parallelogram
A= b x h
What is the area of this parallelogram?
Area of a Triangle
A= �b x h
4 cm
8 cm
Now we can find the area of a complex figure:
9-5 Circles and Circumference
The distance around a circle is its circumference.
This is where we learn about Pi:
p
Not this pie! This one!
Pi is non-repeating, not terminating decimal. (It doesn�t stop and it doesn�t repeat) Pi is approximately 3.14 as a decimal or .
Circumference of a Circle
C = pd
Or
C = 2pr
So, if you have a circle with a radius of 2 inches, what would be the circumference?
9-6 Area of a circle
Area of a Circle
A = pr
Remember, p = 3.14 or
9-7
3-D Figures
A three-dimensional figure is a figure that does not lie in a plane. It has three dimensions: length, width, and height.
A prism is a three-dimensional figure with two parallel and congruent bases. A prism that has all congruent faces is called a cube.
You name prisms by the shape of its base:
Base Shape Name of Prism
Triangle Triangular Prism
Rectangle Rectangular Prism
Pentagon Pentagonal Prism
Hexagon Hexagonal Prism
Heptagon Heptagonal Prism
Octagon Octagonal Prism
A pyramid is a three dimensional figure with 1 polygon for a base. All of the other faces are triangles. You name pyramids by the shape of its base also.
Other three dimensional figures do not use polygons for bases.
A cylinder has two congruent parallel bases that are circles.
A cone has one circular base and one vertex.
A sphere has no base.
9-8 Surface Area of Prisms and Cylinders
The surface area of a 3D figure is the sum of the area of all of its surfaces.
We can take this cube apart to figure out it�s surface area.
How about this cylinder:
9-9 Volume
The volume of a 3D figure is the number of cubic units needed to fill the space inside the figure. A cubic unit is the amount of space in a cube that measures 1 unit long by 1 unit wide by 1 unit high.
Formula for Volume of a Prism
V=B x h
�B� is capitalized because you need to know the area of the base times the height.
For a prism: For a cylinder: