# Making Perpendicular Bisectors: Ex. 9

## DIRECTIONS:

1) Use the POLYGON tool to construct a triangle.
2) Use the PERPENDICULAR BISECTOR (PB) tool to construct the PB's of this triangle's 3 sides.
3) Plot the intersection of these 3 perpendicular bisectors (circumcenter).

## 4)

Construct a circle centered at the circumcenter that passes through any vertex of this triangle. Why does this circle pass through the other 2 vertices of this triangle?

When you're done (or if you're unsure of something), feel free to check by watching the quick silent screencast below the applet.