PLANE SHAPES
CONTENT
- Measuring Perimeters
- Definition of Perimeter
- Perimeter of a Circle
- Perimeter of a Triangle
- Perimeter of a Regular/Irregular Polygon
- Perimeter of a Square
- Perimeter of Rectangles
- Perimeter of a Trapezium
- Perimeter of a Parallelogram
Measuring Perimeters
Definition of Perimeter
Perimeter is the outside boundary or edge of a plane shape. For example, the boundary fence of your school compound is its perimeter. We also use the word perimeter to mean the length of the boundary.
For example, if you take \(200\) paces to walk your school boundary, you could say its perimeter is \(200\) paces.
To find the perimeter of a shape, we add together the length of all sides of the shape.
What is the perimeter of the above shape?
Perimeter \(= 3 + 3 + 2 + 1 + 1 + 2\)
\(= 12 cm\)
Perimeter of a Circle
The perimeter of a circle is called its CIRCUMFERENCE \(= 2πr\)
Where \(r = radius\) of a circle and
\(π = \frac{22}{7}\) or \(3.14\).
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