GeoGebra Classroom

# Reflecting about a Perpendicular Bisector (V1)

In the app below,
1. Use the SEGMENT tool to construct a segment .
2. Use the PERPENDICULAR LINE tool to construct a dashed perpendicular line g that passes through point B. (To do so, simply select the tool, select the segment, then select B).
3. Use the POINT ON OBJECT tool to plot a point C anywhere on the dashed perpendicular line g.
4. Use the POLYGON tool to construct .
5. Use the REFLECT ABOUT LINE tool to reflect ﻿ about line g.

## Keep going! Further directions appear below this app.

6. How would you classify the big by its sides? You may want to use the DISTANCE tool to measure the side lengths and . (Simply select the tool and then select the segment itself.) Be sure to drag point C up and down the perpendicular bisector g after you do this.

7. Use the ANGLE tool to measure . To do this, select the tool, then select the vertices A', A, C in that order. Now use the ANGLE tool to measure . To do this, make sure the angle tool is still selected. Then select the vertices C, A', A in that order. Select the MOVE tool and then move point C up and down line g. What do you notice about the measures of angles ﻿A' and A?

Which of the following statements are true? Select all that apply.

Select all that apply
• A
• B
• C