This challenge gets us looking at concepts like perimeter and a using lines each with a different measure.
Challenge On Boarding – Rectangles and perimeter
What is the perimeter?
Perimeter is a measure of the distance around a shape.
For a rectangle, it can be worked out with a formula. Think of the long sides as being the length and the short sides the width, you need to add up all the sides: length + width + length + width
e.g. 2 + 9 + 2 + 9
As opposite sides of a rectangle are always the same, we can just add length and width and double e.g. (2 + 9) x 2
Rectangles on dotted paper
A rectangle is just a 4 sided shape with 4 right-angles. The smallest rectangle using this dotted grid would be a 1 by 1 square.
On Boarding Challenge
Find the ten smallest rectangles using a dotted grid.
Challenge On Boarding – Non rectangular shapes
Compound shapes
If you stick to the grid and perpendicular lines, you should find a group of familiar shapes!
Polyominoes again!!
All rectangles drawn on a square dotted grid would be polyominoes and the same for other shapes that just use right angles on such a grid.
We can work out the perimeter of polyominoes in a similar way (but without the shortcut)
In the case of the pentomino on the left you just add up all the side lengths
On Boarding Challenge
Which tetromino has the smallest perimeter?
Challenge On Boarding – Polygon paths
What are polygons?
A polygon is a shape with many angles. In fact that is the literal translation.
- Poly = many
- Gon = angle
Polygon Paths
This means that a polygon does not need to be a closed shape. It could be a line with a number of angles.
On Boarding Challenge
Create a polygon spiral. Try just with right angles to start. I’ve started one on the left. What do you notice about the line lengths?
The Challenges
Challenge 1 – The smallest polyomino
Challenge 2 – Polygon Paths
Download or share all of these challenges with this pdf and let us know how you got on with it by tweeting using #momentofmaths and start to see Every moment is a #momentofmaths.
If you would be interested in joining an online maths club session that explores this challenge together over the Easter break, we are running trial club sessions at various times from Tuesday 14th April. To find out more, let us know how you get on with supporting children with maths at home by completing this short questionnaire – https://forms.gle/7K4RwWdfjRb5xxmaA
