text: There is no such thing as the perpendicular bisector of a triangle. You can, however, find the perpendicular bisector of any of the three sides of the triangle. \n\nSuppose you have a triangle called ABC and you wish to find the perpendicular bisector of the side AB. Simply put the point of a compass at point A and open up the compass so that the pencil end is at point B. Then draw a circle. Now put the point of the compass on point B and the pencil end on point A and draw another circle. The two circles will intersect at two points which you might name E and F. Now draw a line through E and F and passing through AB. This line will be the perpendicular bisector of AB.\n\nEvery triangle has three altitudes. In the triangle ABC, the line drawn from C perpendicular to the side AB is an altitude, so is the line drawn from B perpedicular to the line AC, and so is the line drawn from A perpendicular to the line BC.\n\nThe area of a triangle = 1/2 base times altitude. So if you know the area (A) and the base (b) then altitude = 2A/b.\n\nHope this gives you the info you were looking for.