Calculating Perimeter of Shapes

Study Notes

Perimeter is the total distance around the outside of a shape.
It is a one-dimensional measurement, meaning it is measured in units of length such as centimeters, inches, or miles.
Perimeter is the shortest possible distance around a shape, tracing the edge or border.
To find the perimeter of a polygon, add up the lengths of all its sides.
For regular polygons, where all sides are equal, multiply the length of one side by the number of sides.
For irregular polygons, use the known side lengths to deduce the lengths of missing sides, then add up all sides.
When calculating perimeter, always include the units of measurement.

Finding the perimeter of shapes with curves, like circles, can be complicated and requires different methods.
Calculating the perimeter of polygons is simple because they are made up of straight sides.
For triangles, add up the lengths of all three sides.
For rectangles, add up the lengths of all four sides.
For a regular polygon, use the formula: Perimeter = Side Length x Number of Sides.

Perimeter of a Triangle: Side 1 + Side 2 + Side 3
Perimeter of a Rectangle: Length + Width + Length + Width (or 2 x Length + 2 x Width)
Perimeter of a Regular Polygon: Side Length x Number of Sides

Triangle: Sides are 3 cm, 4 cm, and 5 cm. Perimeter = 3 cm + 4 cm + 5 cm = 12 cm.
Rectangle: Short sides are 5 m, long sides are 10 m. Perimeter = 5 m + 5 m + 10 m + 10 m = 30 m.
Regular Hexagon: Each side is 4 cm. Perimeter = 4 cm x 6 = 24 cm.
Irregular Hexagon: Four side lengths are known. Use the known side lengths to deduce missing side lengths. Then add up all six sides to find the perimeter.

Perimeter is the total distance around the outside of a shape.
Measured in units of length (e.g., centimeters, inches, miles)
It's the shortest possible distance around a shape, tracing the edge or border.
To find the perimeter of a polygon, add up the lengths of all sides.
For regular polygons (all sides equal), multiply the length of one side by the number of sides.
For irregular polygons, use known side lengths to deduce missing ones, then add everything up.
Always include units of measurement when calculating perimeter.

Calculating perimeter is simple for polygons because they are made up of straight sides.
Finding perimeter for shapes with curves (like circles) is more complex and requires different methods.
For triangles, add up the lengths of all three sides.
For rectangles, add up the lengths of all four sides (or use the formula: 2 x Length + 2 x Width).
For regular polygons use the formula: Perimeter = Side Length x Number of Sides.

Perimeter of a Triangle: Side 1 + Side 2 + Side 3
Perimeter of a Rectangle: Length + Width + Length + Width (or 2 x Length + 2 x Width)
Perimeter of a Regular Polygon: Side Length x Number of Sides

Add up the lengths of all sides of a polygon to find its perimeter.
For polygons with equal sides, multiply the number of sides by the length of one side to get its perimeter.

A triangle with sides of 3cm, 4cm, and 5cm has a perimeter of 12cm (3cm + 4cm + 5cm = 12cm).
A rectangle with short sides of 5m and long sides of 10m has a perimeter of 30m (5m + 10m + 5m + 10m = 30m).
A regular hexagon with sides of 4cm has a perimeter of 24cm (4cm x 6 = 24cm).
An irregular hexagon with sides of 4 inches, 5 inches, 6 inches, 10 inches, 15 inches and 10 inches, has a perimeter of 50 inches (4+5+6+10+15+10 = 50 inches).