Mammoth Memory

Finding the bisect

To find the bisect of a line you have two choices;

 

Example 1

Use a protractor.

Find the bisect of the following line

Bisect A and B with a protractor

Find the half way point between A & B.

Find the half way point and draw a bisection blob

Now use a protractor to place a point 90°  to the line `A-B`.

Place a protractor and see which angle the blob is at draw a new blob

Draw a line from the half way point to the 90° point.

Draw a perpendicular line through the 2 points

This is now a perpendicular bisect of these two points.

 

Example 2

Use a pencil compass.

Find the bisect of the following line.

Bisect this line using a pencil compass

Find the half way point between A & B.

Find the half way point and draw a bisection blob

Now use a pencil compass that is open more than half way on each point A & B.

Put the compass on A and draw a curve slightly off centre so the mid point goes behind the curve

Put the compass on B and draw a curve slightly off centre so the mid point goes behind the curve

Now join the two arc intersections.

Where the curves intersect draw a line through both this is the perpendicular line

This is now the perpendicular bisect of A & B.

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