Circumcentre

Marks the circumcentre: the point the same distance from all three corners. Ruler and compass only.

All parts

Part 1 of 3: Bisect ABStep 1 of 11Compass

The centre is the same distance from A and B, so it lies on the line that cuts AB in half. Put the point of your compass on A.

Keys: left and right arrows step, Space plays or pauses, Escape goes back to all constructions.