Patterns with “Pentagonal” Triangles

 

Ideas for activities with children

 

  • Let children cut up a pentagon into the three triangles shown here and compare the angles in the triangles and find which are equal.                         

Click on the pentagon for a template you can copy and print out.

·        Let children play around with sets of the “pentagonal” triangles and discover for themselves what kinds of shapes can be made.

 

 

·        Show children examples of the finished stars. Challenge them to work out which triangles have been used, and how they have been put together. Challenge children to create a finished star themselves.

 

·        When they have made the stars let them identify all the new shapes that emerge when the stars are put against the light.  In each case within the star smaller examples of  two kinds of “pentagonal star will emerge which are similar to the originals.

or

·        Challenge children to make the patterns by following the instructions as given below.

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Patterns with “Pentagonal” Triangle 1     (72,72,36)

 

The first set of patterns all use a triangle with angles of 72,72, and 36 degrees.

 

Click here for some outlines you can print off and use to make the stars below.

 

 

 

Some hints on paper to use and how to glue the triangles.

Use thin coloured  paper to start with.  If you become

 more expert then try tissue paper but this can be hard

 to handle

 

Arrange all the triangles in place first to make sure they

 make the complete shape. If you glue the first pair

 straight away you may find that the last triangle is way

 out.

 

When you have all triangles in place, adjust them  to

create the final pattern. Hold the first pair in place with

 pressure from your fingertip. Lift the flap of the upper

triangle and spread a little glue ( I use a glue stick) on

 the triangle underneath. Let the upper triangle fall back

into place a press to fix.

 
 

 

 

 

 


Pentagon and Nesting Star

 

Overlap 5 triangles to create a pentagon.

 

 

 

 

 

 

 

 

 

 

Discover a nested 5 pointed star when you put the pentagon on the window. Hold the pattern in place with clear plastic. (Book covering film works well. Rub it with a sock or soft toy to generate a static charge which will hold it in place)

 

Can you recognize the triangles that appear?

 

 

Pentagonal Star

Once again use 5 triangles but overlap as shown here.

 

 

 

 

 

 

 

 

 

         

Put the star on the window and discover a 5 pointed star nested inside.

 

 

 

 

 

Hollow Pentagonal Star

 

Another method of creating a star using 5 of the triangles is shown here. It is not quite as easy as the previous methods but creates a very elegant window star.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Hollow Pentagonal Star         

 

 

Variable Overlap Star

 

You can decide to overlap the triangles any amount you like, as long as it is the same for each pair.

 

Here they are overlapped so that the mid points coincide.

 

 

 

 

 

 

 

 

 

 

Here they were overlapped a smaller amount.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Patterns with “Pentagonal” Triangle 2  

 

Use this triangle for all the patterns below. It is triangle with angles

of  36, 36, and 108 degrees.

 

Click here for an outline you can copy and print out.

 

 

 

 

 

 

 

Hollow Pentagon

 

Overlap and glue in place like this

 

 

 

 

 

 

When you place the Hollow Pentagon

against the light a pentagonal star

appears inside the pentagon.

 

 

 

 

 

 

 

 

Hollow Pentagonal Star (1)

 

Use 10 triangles and combine in pairs. Then overlap them to create a star.

 

 

 

 

 

 

 

 

 

 

 

Against the light

 

         

 

 

 

 

Hollow Pentagonal Star (2)

 

The same star pattern can be created using only 5 triangles but the placing is slightly more difficult.

 

 

 

 

 

 

 

 

 

Against the light a nested 5 pointed star appears!

 

 

 

 

Hollow Pentagonal Star (3)

 

Use 10 triangles and first combine them in pairs like this.

 

 

 

 

Then overlap the pairs to create a star with a larger hollow pentagon at the centre.

 

 

 

 

 

 

 

 

 A pattern like this emerges against the light.

 

 

 

 

 

 

 

 

 

 

Ten Pointed Star

 

Overlap 5 triangles to create this rather unusual star. Notice how the bases of the triangles are in a straight line but do not overlap.