General instructions: At the bottom of the page you should see a screen with a trapezoid, that can be moved. If you don't see this, you may need to use another browser (if you're using Explorer, try Firefox and vice versa), or you may need to update the Java on your computer. You can get it for free here: http://www.java.com/en/download/index.jsp
In the applet window below, there are several objects that you can move by clicking and dragging. Generally speaking, you can click and drag points, but not lines. I have tried to hide all of the dots that can't be dragged, so it should be that all of the (red) dots you can see, you can click on and drag to new positions.
If you want to measure something in the applet, you can drag the length measurement segment around next to it to check its length, or the angle measurement tool to check an angle, or you can drag the parallel lines over next to a pair of lines to check if they are parallel.
The trapezoid: The trapezoid you see is a trapezoid-maker. This means that if you drag the points around in such a way that you still have a 4-sided figure (making a triangle or crossing one line over another isn't allowed!), the figure you have is an example of a trapezoid.
An unusual thing about trapezoids: Unlike most other geometric shapes, there isn't just one definition that gets used for a trapezoid, there are two! So, depending on which book your elementary/middle/high school used, some of the properties you may find about trapezoids using this trapezoid maker may be different from properties of trapezoids that you have learned about before.
To do: Find as many properties as you can that are always true for trapezoids, and record them on your recording sheet. Use this trapezoid maker to decide what properties trapezoids have.
Your choice: Some people like to measure things to check to make sure that what they think they see is correct. That's why I gave you the measurement tools that are on the right side of the applet. You don't have to use them if you are confident of your estimates.
Be sure to: drag around the trapezoid maker to make lots of different shapes and sizes of trapezoids. Make sure that your properties are true for all of the trapezoids.
trapezoid