# Exploring Perpendicular Bisectors: Part 1

In the app below,

- Use the SEGMENT tool to construct a segment with endpoints
*A*and*B*. - Use the MIDPOINT tool to construct the
**midpoint**of this segment. It should be named*C*. - Use the PERPENDICULAR LINE tool to construct a line perpendicular to segment that passes through the segment's midpoint
*C*.

## This line you've just constructed is said to be the PERPENDICULAR BISECTOR of the segment AC. Keep going: More directions appear below.

4. Use the POINT ON OBJECT tool to plot a point

*D*on the perpendicular bisector. 5. Now construct segments and . 6. Now select the MOVE tool. Then select (highlight) segment . Select the style bar icon (circle + triangle symbol in the upper right corner). Where it says "**Aa"**, select**Value**. This will show its length. ' 7. Repeat step (6), yet this time for segment .Now drag point *D* all along the perpendicular bisector of segment . What do you notice? Be specific!

Use the ANGLE TOOL to display . What is it? Why does it measure what it does?