In these lessons, we will learn how to construct the perpendicular bisector of a line segment using a compass and a straightedge or ruler. We will also learn how a perpendicular bisector can be used to form a rhombus or kite and to find the midpoint of a line segment.
Related Topics: More Geometric Constructions & Geometry Lessons
The perpendicular bisector
of a line segment AB
is a line that divides the line AB
into two equal parts at a right angle.
Construct a perpendicular bisector of the given line segment AB.
Step 1 : Stretch your compasses until it is more then half the length of AB. Put the sharp end at A and mark an arc above and another arc below line segment AB.
Step 2 : Without changing the width of the compasses, put the sharp end at B and mark arcs above and below the line segment AB that will intersect with the arcs drawn in step 1.
Step 3 : Join the two points where the arcs intersect with a straight line. This line is the perpendicular bisector of AB. P is the midpoint of AB.
The above construction steps can also be used to construct an isosceles triangle
or a rhombus
We have constructed 4 isosceles triangles; AQB, ARB, QAR and ARB. We have also constructed a rhombus AQBR.
The following video shows how to construct a perpendicular bisector of a line segment.
The following video shows how to bisect a line segment using only a compass and straightedge.
Uses of a Perpendicular Bisector
Constructing a Perpendicular Bisector with Isosceles Triangles.
Forming either a Rhombus or a Kite and then joining opposite vertices with perpendicular diagonals bisecting each other.
How to Find the Midpoint of a Line Segment Using a Perpendicular Bisector
In this tutorial about geometric constructions, we walk through how to locate the mid-point of a line segment without a ruler, using a math compass and a straightedge. We can find the mid-point by draw a perpendicular bisector.
Constructing the Perpendicular Bisectors of the Sides of a Triangle
This video explains how to construct the perpendicular bisectors of the sides of a triangle and define the properties of the perpendicular bisectors of the sides of a triangle.
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