Working out Perimeter/Circumference

Working out Perimeter/Circumference

How to work out the Perimeter or Circumference of shapes

Perimeter of Polygons (straight line shapes)

• Polygons are shapes that have edges made up of straight lines (i.e. no curves/round edges), for example, squares, rectangles, triangles, pentagons, etc

• To find the Perimeter we simply add up the lengths of all the sides

• Remember: a square has sides all the same length

Multiple Choice

Perimeter of triangle?

• 32 units

• 20 units

• 10 units

• 17 units

Multiple Choice

Find the perimeter of this triangle.

• 12 in

• 22 in

• 18 in

• 24 in

Multiple Choice

Find the perimeter of this triangle.

• 26 cm

• 30 cm

• 21 cm

• 16 cm

Multiple Choice

What is the perimeter of the rectangle? (Hint: top matches the bottom, left matches the right!)

• 28 sq feet

• 28 feet

• 48 feet

• 48 sq feet

Multiple Choice

Farmer Jose built a fence around his rectangular pig's pen. The fence was 10 feet long and 7 feet wide. How many feet of fencing would he need for his pig's pen?

• 70 feet

• 17 feet

• 34 feet

• 36 feet

Multiple Choice

The diagram shows a regular hexagon.

What is its perimeter?

• 20

• 24

• 25

• 30

Multiple Choice

What is the perimeter of this shape?

• 33 cm

• 23 cm

• 36 cm

• 40 cm

Circumference of Circles (the distance around a circle)

Multiple Choice

Does this picture show the diameter or radius of a circle?

• Diameter

• Radius

Multiple Choice

What is the circumference of this circle using 3.14 for Pi?

CALCULATOR ALLOWED

• 3.14 cm

• 37.68 cm

• 24 cm

• 68.4 cm

Multiple Choice

The diameter of a bowl is 14 cm. What is the circumference of the bowl using 3.14 for Pi?

CALCULATOR ALLOWED

• 28 cm

• 43.96 cm

• 87.96 cm

• 7 cm