Perpendicular on a line from a given point

Question

How can I draw a perpendicular on a line segment from a given point? My line segment is defined as (x1, y1), (x2, y2), If I draw a perpendicular from a point (x3,y3) and it

Answer 1

Find out the slopes for both the lines, say slopes are m1 and m2 then m1*m2=-1 is the condition for perpendicularity.