Growing changes
This is a level 3 geometry activity from the Figure It Out Series. It is focused on recognising changes in properties with enlargement. 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 outcoes:
- Recognise changes in properties with enlargement.
Growing changes
Achievement objectives
GM3-6: Describe the transformations (reflection, rotation, translation, or enlargement) that have mapped one object onto another.
Required materials
- overhead projector
- a large sheet of square grid paper
- transparencies
- Figure It Out, Level 3, Geometry, "Growing changes", page 24
See Materials that come with this resource to download:
- Growing changes activity (.pdf)
Activity
Warn students not to move the overhead projector while it is switched on, or the bulb may blow.
If students are having difficulty with the triangle and the circle, you could start with a simple square, as shown in Activity 1:
B is an enlargement of A. The scale factor is two.
Activity 1
a. The shape stayed the same, and the vertices remained right angles.
b. The length of the sides and the area
Activity 2
a. Features that have stayed the same are the shape, the vertices, and the ratio of side lengths. Features that have changed are the length of the sides and the area.
b. Features that have stayed the same are the shape and the centre point of the circle. Features that have changed are the circumference, the radius, the diameter, and the area (all increased).
The quality of the images on this page may vary depending on the device you are using.