Learning Resources

Investigation 2: Properties of Chords (Alternate Method)

Instructions for running the interactive window

The circle you will work with has three chords  CD, EF, and GH drawn along with the perpendiculars to each of them. The chord and the perpendicular are in matching colors. The perpendiculars can be moved by clicking and holding the mouse button down on the points where they intersect the cords.

Start with point J and move the perpendicular until it passes through the centre of the circle, then record the length CJ and DJ as required in Step E of the Investigation in your text book. You need only consider the first two digits in the measurements as you will not likely be able to be more accurate with the mouse than that. Repeat this for the other perpendiculars using points I and K and comparing EI with FI, and GK with HK. Make a note of these segments now on a piece of paper before you begin.

After you have done that for the three chords given, move them to various locations by clicking on one of their end points and dragging them about. Then again compare the same values as above.

Once you have started to investigate the different positions of the perpendiculars and chords, the diagram may get messed up. If it does, to return to the original screen you started with, simply press r. This will restore the screen to the original diagram.

When you are finished with the investigation, simply close the window and you will be returned to this page.

Based on what you observe, answer Step H of the Investigation on page 210 in your text.