[size=150][color=#ff0000][b]In this applet, you will explore the radius and diameter of a circle. [br][/b][list][*][b]You may change the size of the radius by clicking and dragging the red button. [/b][/*][*][b]You can click and drag on any points identified in the circle to move them[/b][/*][/list][/color][/size]
[size=150][b][color=#ff0000]In the applet below, which segment represents the radius of the circle?[/color][/b][/size]
In the applet above, line segment AC represents the radius of the circle.
[size=150][b][color=#ff0000]In the applet below, which segment represents the diameter of the circle?[/color][/b][/size]
In the applet above, line segment BD represents the diameter of the circle.
[size=150][b][color=#ff0000]In the applet below, which point represents the center of the circle?[/color][/b][/size]
In the applet above, point C represents the center of the circle.
[b][color=#ff0000][size=150]Click and drag point A around the circumference of the circle. Does the measure of the length of the radius ever change? Why or why not?[/size][/color][/b]
The definition of a circle is the set of all points that are equally distant from the center. Since the radius of any circle is the segment with one endpoint at the circle's center and the other on its circumference, its length will be that distance.
[size=150][b][color=#ff0000]Click and drag point A so it sits atop point B. What is true about the relationship of the radius to the diameter?[/color][/b][/size]
The radius is the same length as 1/2 the diameter. The length of the diameter is 2x the length of the radius.