Perimeter of 2D shapes
To find the perimeter of 2D shapes simply add up the length of each sides!
Remember regular polygons have sides with the same lengths:
Circumference of circles
To find the circumference of a circle use the formula circumference = diameter x π. Eg.:
Circumference = 6 x π = 18.85 (to 2 dp)
Perimeter of compound shapes
Compound shapes are shapes that are made up of more than one. For example:
For example this shape can be divided into two rectangle.
- A regular pentagon has a length of 4 cm, what is the perimeter of the pentagon?
- Your answer should include: 20cm / 20
- A regular polygon has a perimeter of 50 mm, each side is 8 ⅓mm what is the name of the shape?