Compass shapes
This is a level 4 geometry strand activity from the Figure It Out series. It is focused on constructing shapes and patterns using a compass. A PDF of the student activity is included.
About this resource
Figure It Out is a series of 80 books published between 1999 and 2009 to support teaching and learning in New Zealand classrooms.
This resource provides the teachers' notes and answers for one activity from the Figure It Out series. A printable PDF of the student activity can be downloaded from the materials that come with this resource.
Specific learning outcomes:
- Construct shapes and patterns using a compass.
Compass shapes
Achievement objectives
GM4-5: Identify classes of two- and three-dimensional shapes by their geometric properties.
Required materials
- Figure It Out, Levels 3–4, Geometry, "Compass shapes", page 12
- compass
- ruler
- classmate
See Materials that come with this resource to download:
- Compass shapes activity (.pdf)
Activity
This activity initially helps students to recognise that the circumference is approximately six times the length of the radius. However, the objective of the activity is to give them practice in using the compass to make geometric designs beginning with a circle. This becomes a satisfying artistic activity, but you could also encourage them to use their design or logo to explore symmetry.
For example, the logo shown in the book has rotational symmetry of order 3 and three lines of reflective symmetry (m1, m2, m3). (Point A on the diagram below is the centre of rotation.)
Another design made from the original inscribed hexagon could be:
This design has rotational symmetry of order 6 and six lines of reflective symmetry.
Examining designs for reflective or rotational symmetry follows on from the activity on page 21 of Geometry, Figure It Out, Level 3.
1.
a. Six times
b. Your diagram should look like this:
2.
Make six equally spaced marks on the circumference using the radius as the length of each space. Join every second point to draw an equilateral triangle.
3.
Practical activity
4.
Practical activity
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