by David Wise

Note: I recommend that this page be printed out, so that the instructions are easier to follow.

**Click here** to link to a new GSP sketch to complete a construction
of a rectangle.

When completing a construction, use the definition as a guide.

- Construct two points, A and B.
- Construct segment AB.
- Select point A and segment AB and construct a perpendicular line.
- Select point B and segment AB and construct a perpendicular line.
- Select the perpendicular line to segment AB that passes through point B and use the Point on Object construction.
- Select point C and line BC and construct a perpendicular line.
- Construct the intersection point of the two lines.
- Construct the segments BC, CD, and DA.
- Select and hide the original lines.
- Click and drag any vertex and/or side to make sure that your construction always holds true for the definition of a rectangle.
- Using the selection tool, click and drag around your constructed rectangle, so that the entire rectangle is selected. Use the work menu to create a script.

Using only the definition of a rectangle, what measurement of the sides of a rectangle must be used to support the claim that your construction is of a rectangle?

Extension:

Find another way to construct a rectangle.

If you have any questions while trying to complete this investigation,
or suggestions that would be useful, especially for use at the
high school level, please send e-mail to **esiwdivad@yahoo.com**.

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the Table of Contents.