Perimeter+and+Area

**Click on the video below and learn all about the differences between perimeter and area.**
media type="youtube" key="D5jTP-q9TgI" height="345" width="420"

Perimeter is the outside of an object. We add all the sides together to get a perimeter.
 * Perimeter**

**Perimeter Power point**
Here is a simple explanation of how to calculate a perimeter.

**EXAMPLES**

 * **To find the perimeter of a polygon, take the sum of the length of each side.** ||
 * Example 1: || Find the perimeter of a rectangle with sides measuring 5 centimeters, 9 centimeters and 11 centimeters. ||
 * Solution: || P = 5 cm + 9 cm + 11 cm = 25 cm ||
 * Example 2: || A has a length of 8 centimeters and a width of 3 centimeters. Find the perimeter. ||
 * [[image:http://www.mathgoodies.com/lessons/vol1/images/tab.gif width="10" height="2" caption=" "]] ||
 * Solution || P = 8 cm + 8cm + 3 cm + 3 cm = 22 cm ||
 * Example 3: || Find the perimeter of a with each side measuring 2 mm. ||
 * Solution: || P = 2 mm + 2 mm + 2 mm + 2 mm = 8 mm ||
 * Example 4: || Find the perimeter of an with each side measuring 4 centimeters. ||
 * Solution: || **P = 4 cm + 4 cm + 4 cm =12cm** ||
 * Solution: || **P = 4 cm + 4 cm + 4 cm =12cm** ||

**Don't confuse perimeter with area. Area is the inside of an object. To determine area we multiply. To determine perimeter we add all the sides together.**
Area of a Rectangle A very simple shape is the “Rectangle”. A Rectangle has an Area of Base x Height, which is sometimes called Length x Width, or Length x Height.



Image Source: http://www.k6-geometric-shapes.com We can prove this formula by drawing a whole bunch of rectangles, and counting how many squares are inside them. Work out each area using a) counting the squares method b) area formula bxh

Image Source: http://www.geom.uiuc.edu However, not all shapes are as simple as a Rectangle. If we push a Rectangle sideways, we from a Parallelogram. Area of a Parallelogram

The Area of a Parallelogram is Area = base x height Here is a video all about the Area of a Parallelogram. media type="youtube" key="dLZd1MD9kaw" height="345" width="420"

How do you like this for a real life Parallelogram!

Image Source: http://www.elec-intro.com

Click on the following link for some area calculations for you to try

Now you can check your answers in the following PDF file. Click on the link

Click on the following link and try some mixed area and perimeter calculations. [|Area and Perimeter]

====There are many formulas we need to use in math in determining perimeter and area of objects. The following power point gives an overview of all the formulas. Read this and take notes on each fomula and how it is used.====

==

Online Area and Perimeter Games

@http://www.mrnussbaum.com/zoo/index.html

Here is an Online learning Activity to do that is all about Perimeter and Area



@http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/perimeter_and_area/index.html



It is necessary to get right on the corners of the initial symbols, get the hand symbol, and then drag the items around the grid to make them fit according to the Perimeter and Area rules given. Note that final areas of items are not allowed to overlap. However, it might be necessary to do some overlapping while making the shapes. @http://www.mathplayground.com/PartyDesigner/PartyDesigner.html

Play this interesting game to find the relationship between Perimeter and Area. @http://pbskids.org/cyberchase/games/perimeterarea/index.html Have some fun learning about irregular shaped areas with this Tangrams game. @http://pbskids.org/cyberchase/games/area/index.html A Challenging Area and Perimeter Game

= Area of a Triangle =

We could work out the area of a triangle by drawing it to scale on grid paper and counting squares.

Image Source: http://www.geom.uiuc.edu

But it is much easier to measure the triangle’s base and height, and use a mathematical formula to calculate the area. This formula can be worked out very easily, because a Triangle is half of a Parallelogram. Area of any Parallelogram is Area = base x height. So the area of any Triangle is : Area = 1/2 x base x height. Here is a video that explains how this works. media type="youtube" key="2avSR3Izbss" height="345" width="560"

==The area of a [|triangle] is always half the [|product]of the height and base. **A=½ (base × height)**==





Here is an example of how we calculate the area of a triangle.

Image Source: http://www.loisterms.com

Area of a Trapezium (or Trapezoid).

This shape is a bit like a Parallelogram, except that it only has two parallel sides. Australians call it a “Trapezium”, and Americans call it a “Trapezoid”.

Image Source: http://www.mathwarehouse.com

Here is a quick little video to help remember how to calculate the area of a Trapezium. media type="youtube" key="qlxawNewXiY" height="345" width="420"

Area of a Rhombus A Rhombus is a Parallelogram that has all four sides equal. We can work out its area using Base x Height, but we can also work out the same area by multiplying the two internal diagonals together, and dividing by 2.

Image Source: http://www.thefreemathtutor.com Answers to Rhombus Questions:

Q1. 418 sq cm, 41600 sq mm, 0.0006 sq m.

Q2. 91 sq cm

Q3. (1000×2) / 10 = 200mm.

Q4. (120×2) / 30 = 8m. Area of a Kite A Kite is a similar shape to a Rhombus, and its area is obtained by multiplying together its diagonals.

Image Source: http://www.coolmath.com

Summary of Area Formulas Here is a set of formulas that are used in mathematics for finding areas. Image Source: http://www.math-videos-online.com

Image Source: http://www.grc.nasa.gov

Online Activities Here is an activity on Areas of Rectangles, Triangles, and Parallelograms. (This one takes a little while to load up).



Click the question mark to enter your answer, then click the ok to check your answer.

@http://www.bbc.co.uk/schools/ks3bitesize/maths/measures/area/activity.shtml

[|Radius and Diameter]
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Identify radius and diameter.