Performing Enlargements

This activity involves the use of tools to plot points and draw lines. If you are not sure how to do that on Geogebra, watch this video. Also, note that there is a glossary of key terms at the end of the activity.

Drag the slider to expand this shape, pay attention to what happens when the scale factor is greater than 1 and when it is less than 1. Try moving the scale factor to be less than 0 and see what happens. You can move the points of the triangle and the cen

What do you notice happens when the scale factor is greater than 1?

What do you notice happens when the scale factor is less than 1?

What do you notice happens when the scale factor is less than 0?

What happens to the enlarged image when you move the vertices of the original object?

Enlarge the shape by a scale factor of 2 from the centre of enlargement (1,3).

Enlarge the shape by a scale factor of 3 from the centre of enlargement (3,4).

Enlarge the shape by a scale factor of 2 from the centre of enlargement (2,2).

Enlarge the shape by a scale factor of 1/2 from the centre of enlargement (10,5).

Enlarge the shape by a scale factor of 4 from the centre of enlargement (0,3). You must place the centre of enlargement on the grid yourself this time.

Glossary

Vertices - Corners of the shape.[br]Scale Factor - The value multiplied by length of each side of the original shape to find the size of the enlarged image.[br]Centre of Enlargement - The position that the enlargement originates from, this is where you should begin counting from to determine the position of the enlarged image.