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## Proportions

These two proportion applets were created by *Duane Habecker*

**Exploring similar triangles**: Move the vertices of two similar triangles and watch the lengths change. Find all the instances of equal ratios in the similar triangles.

**Similar triangles with missing lengths**: Two triangles are similar but two of the side lengths are missing. Move the vertices of the triangles to create a problem and then use proportions to find the missing lengths.

- Download the
*ggb*file.

- Download the

Two applets by *Roger Moss*:
Visualising direct and inverse proportion: change the enlargement factor and see how x and y vary.

**Direct proportion**: Move the sliders and see the coordinates change.**Indirect proportion**: See how the area of a rectangle under any point stays constant.