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Angle Bisector Definition (SA.8)

In the applet below, the blue ray is said to be an angle bisector of angle BAC. The gray slider adjusts the entire measure of angle BAC. The black slider dynamically illustrates what it means for a ray to bisect an angle. Interact with this applet for a few minutes, then answer the questions that follow.


From what you've seen, describe what it means for a ray to bisect an angle. In your description, avoid using the words or phrases middle, down-the-middle, half. If you need a hint, refer to terminology seen from this worksheet.

Use the Point on Object tool to plot a point F anywhere on the angle bisector. Then use the Angle tool to find and display the measure of angle BAF and CAF.

Question 2

Did the measure of the angles BAF and CAF reflect (i.e. illustrate) your response to Question 1?

Open the Angle Bisector Construction activity and complete it.