Transformations - Enlargements

Author:
joventura
This applet is designed to explore what happens when enlarging a shape by different scale factors about the origin.
When enlarging an object, there are two things to consider. Where the centre of enlargement is, and the scale factor. We shall call the original shape the Object, and the transformed shape the Image. Move the slider 'a' to see what happens when enlarging by different scale factors. Answer the following questions: 1) What scale factor maps the object onto itself? 2) Which scale factor describes a rotation around the origin? How can you describe the rotation? 3) What happens when the scale factor is negative? 4) What values of 'a' make the image smaller than the original object? 5) What scale factor maps the point F to (6, 2)? 6) What scale factor maps the point E to (-4.5, 3)? 7) What scale factor maps the point A tp (-0.5, -0.5)? 8) Set 'a' to -1. Instead of using enlargment, you can map the Object to the Image in 2 reflections. Work out what lines of reflection you would use - there is more than 1 way. You can move the vertices of the shape to see what happens to triangles and other shapes when enlarged. You can also double click on 'a' and change the scale factor increments.