Math 5.1 & 5.2 Definitions

Honore Geo

Perpendicular Bisector

A line that cuts a side in half and makes a right angle (90°).
→ All of them meet at the circumcenter.

Circumcenter

The spot where all the perpendicular bisectors meet.
→ It’s the same distance from every corner of the triangle.
→ Can be inside, outside, or on the triangle.

Angle Bisector

A line that splits an angle into two equal angles.
→ All of them meet at the incenter.

Incenter

The spot where all the angle bisectors meet.
→ It’s the same distance from every side of the triangle.
→ Always inside the triangle.

Median

A line from a corner to the middle of the opposite side.
→ All of them meet at the centroid.

Centroid

The spot where all the medians meet.
→ It’s the triangle’s balance point (center).
→ It’s 2/3 of the way from the corner to the middle.

Altitude

A line from a corner that goes straight down (90°) to the other side.
→ All of them meet at the orthocenter.

Orthocenter

The spot where all the altitudes meet.
→ It can be inside, outside, or on the triangle.