Dilating Triangles

Using this Geogebra applet will allow students to explore the concept of geometric dilations.

What is the value of k when the figure is a reduction?

What is the value of k when the figure is an enlargement?

Based on this information, what does k represent?

What happens to the figure when k = 1? Why does this happen?

How can we find the value of k if we are only given the lengths of the sides of the figure?

Use the slider to change the dilation factor, observe what happens to the coordinates of the image.

How are the coordinates affected by changing the scale factor?

Now create two dilations of the pentagon ABCDE with center of dilation at point F. One dilation must be a stretch and the other must be a shrink.