Sign in to view assessments and invite other educators
Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.
Points
Here is a line
Here is an angle:
For each angle that you draw, explain to your partner how each straightedge and compass move helps you to bisect it.
For each angle that your partner draws, listen carefully to their explanation. If you disagree, discuss your thinking and work to reach an agreement.
We can construct a line that is perpendicular to a given line. We can also bisect a given angle using only a straightedge and compass. The line that goes through the vertex of an angle to divide it into two equal angles is called the angle bisector. Both constructions use 2 circles that go through each other’s centers:
To construct a line perpendicular to line
To construct an angle bisector, start by finding 2 points, labeled here as
One large circle with a center point and a central angle. Two small circles centered on the intersection of central angle and large circle. A line is drawn from the intersection point of the two small circles through the center of the large circle.
In fact, we can think of creating a perpendicular line as bisecting a 180 degree angle!
An angle bisector is a line through the vertex of an angle that divides it into two congruent angles.
In this diagram, the dashed line is the angle bisector.