New
New
Year 10
Foundation

Checking and securing understanding of perimeter for standard shapes

I can calculate the perimeter of rectangles, triangles, parallelograms and trapeziums efficiently.

New
New
Year 10
Foundation

Checking and securing understanding of perimeter for standard shapes

I can calculate the perimeter of rectangles, triangles, parallelograms and trapeziums efficiently.

Lesson details

Key learning points

  1. The perimeter of any polygon can be found by adding but this may be time consuming.
  2. By considering the properties of the shape, there may be a more efficient method.
  3. There is a formula to find the perimeter of rectangle.
  4. Missing side lengths can be found if the perimeter is known.

Common misconception

"To find the perimeter, you just add together the numbers that you see."

The perimeter of a polygon is the sum of the lengths of all the sides of that shape. Not all sides have their lengths explicitly written. This could be due to sides having equal length, and the lengths of some sides shown with hash marks.

Keywords

  • Perimeter - The perimeter is the distance around a 2D shape.

  • Polygon - A polygon is a flat (2D), closed figure made up of straight line segments.

It can be helpful to encourage students to systematically go around the edges of a polygon one by one to check if its side lengths are known (or can be found out) before explicitly finding the perimeter of that shape.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
The is the distance around a 2D shape.
Correct Answer: perimeter
Q2.
Which units can be used for perimeter?
Correct answer: cm
cm²
cm³
grams
litres
Q3.
1 cup is equivalent to 16 tablespoons. A quarter of a cup is equivalent to tablespoons.
Correct Answer: 4, four
Q4.
Approximately 28 grams are equivalent to 1 ounce (oz). There are 16 ounces in a pound. 1 pound is approximately __________ grams.
1.75
12
44
Correct answer: 448
Q5.
1 kilometre = centimetres.
Correct Answer: 100 000, 100000, 100,000, one hundred thousand, 100 thousand
Q6.
Starting with the smallest length, put the lengths in order of size.
1 - 35 000 mm
2 - 0.35 km
3 - 350 000 cm
4 - 35 000 m

6 Questions

Q1.
The perimeter of the rectangle is cm.
An image in a quiz
Correct Answer: 50, fifty, 50 cm
Q2.
The perimeter of the parallelogram is __________ units.
An image in a quiz
7
8
12
14
Correct answer: 16
Q3.
The perimeter of the trapezium is 26 units. The length of the sloping side is units.
An image in a quiz
Correct Answer: 8, eight
Q4.
The regular hexagon has perimeter 30 cm. $$a$$ = .
An image in a quiz
Correct Answer: 5, five, 5 cm
Q5.
Jacob draws a rectangle. Sofia draw a parallelogram (without right angles). Each shape has the same base and height. Which statement is true?
The rectangle has a greater perimeter than the parallelogram.
Correct answer: The parallelogram has a greater perimeter than the rectangle.
Both shapes have the same perimeter.
Q6.
The perimeter of the rectangle is 28 cm. $$m$$ = .
An image in a quiz
Correct Answer: 6, six, 6 cm