Bisecting Line Segments and Angles

Slideshow 40, MathematicsMr Richard SasakiRoom 307

OBJECTIVES

• Learn how to bisect a line segment with a perpendicular line

• Learn how to bisect an angle

LINE SEGMENT BISECTION

With the use of a compass, we can bisect a line segment with a line perpendicular to this.Let’s draw an 8cm line segment being bisected by a perpendicular line .

First, draw an 8cm line segment .

LINE SEGMENT BISECTIONNext, with the compass we measure anywhere over half of the length of

With this radius, from P, we draw a mark above and below the diagram where each mark contains the half-way point on either side.

LINE SEGMENT BISECTIONKeeping the compass at the same radius, we place the point at Q and again draw marks above and below the line segment that hopefully cross.

We would then connect the crosses together to make a perpendicular line.

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Complete Questions 1 – 3!

BISECTING ANGLESTo bisect an angle (), we first mark two line segments , (or lines or rays) the same distance from the angle to be bisected.

(This can be one arc if preferred.)

From each mark made, we then make marks between the line segments, where you think the bisection will go (in the middle).Finally, draw the ray (or whatever) and label it!

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