# 199. Video of the week: Constructing Pentagons

I came across this video whilst looking for 3D construction ideas for a 7 year olds homework. It is a very easy to follow video explaining how to construct a pentagon using a ruler, pencil anda  pair of compasses. When I say easy, I mean it. The voiceover is in Spanish and all my knowledge of Spanish comes from watching ‘Dora the Explorer’ with the children – and I still understood how to do this.

Not only will it help pupils improve their fine motor skills using compasses, you could also ask more able students why it works. You could also ask Spanish speakers to translate!

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# 80. Sunshine and constructions

Here is a quick consolidation/revision/application task for constructions, which involves very little preparation. If the sun isn’t shining you could always adapt this for indoors.

Equipment
Chunky chalk (look in your local pound shop)
String
Straight edge and tape measure or just a metre stick
Usual classroom textbook/notes

A company has sketched out a set of new signs and it is your job to accurately draw them without a protractor. The task is differentiated by sign design.

Sign 1
Made from a rectangle and two equilateral triangles.

Sign 2
Same as sign 1, but with a border of constant width

Sign 3
Made from a rectangle, an equilateral triangle and a right angled isosceles triangle.

Sign 4
Same as sign 3, with a border of constant width.

Skills used:
Constructing an equilateral triangle (1,2,3,4)
Constructing the locus of a moving point (2,4)
Bisecting an angle (3,4)
Constructing a perpendicular bisector (optional in all cases)

Activity
Once the signs are allocated, each group must present a plan to the teacher on how they will draw it. They may use their notes, textbooks and smartphones (if your school allows this).

When the groups are outside, they can easily increase their understanding by moving on to the next design or developing their own arrows.

Examples of work

Health Warning!
These signs, when viewed from the end, can look rather like rockets. All I will say is:
rockets + construction arcs + pink chalk + teenager boys’ level of humour= ….

# 38. Quick Constructions

A quick idea today.

Most Maths Departments use squared paper exercise books. Great for lots of mathematical concepts, but not constructions.

How many times have you seen a perpendicular bisector drawn using the right angle from the squared paper with some freehand scrawled ‘construction’ lines?

The solution to this topic is so simple – use plain paper. But then they forget to stick in their book or lose it!

The best activity I have used is to use folded A4 plain paper for the whole constructions topic. Pupils must annotate their work with instructions and revision hints. When you finish, you give them a coloured paper or card cover to attach. You could include a printed summary of skills on it.

The final homework is to illustrate the cover of the booklet with their favourite technique or related design.

This task is so easy to do, involves little preparation, creates a useful revision resource and promotes independent learning.

(The diagram is from BBC bitesize website which has some nice revision activities on this)