Talking about points “equidistant from the sides” requires a precise definition of the distance between a point and a line. Among all the segments joining the point to the line, the shortest is the perpendicular one.
Definition — Point-line distance
The distance of a point from a line is the length of the segment , where is the foot of the perpendicular from to .
Links
Topics: Euclidean geometry
Concepts: Height · Point-line distance · Line