| 1. Draw a line segment which will become one side of the angle.
(Skip this step if you are given this line.) The exact length is not important. Label it PQ. P will be the angle's vertex. |
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In the next 3 steps we create the
perpendicular bisector of PQ.
See Constructing a perpendicular bisector of a line segment
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| 2. Set the compass width to just over half the length of the line segment PQ. |
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| 3. With the compass point on P then Q, draw two arcs that cross above and below the line. |
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| 4. Draw a line between the two arc intersections. This is at right angles to PQ and bisects it (divides it in exactly half). |
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| 5. With the compass point on the intersection of PQ and the perpendicular just drawn, set the compass width to P |
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| 6. Draw an arc across the perpendicular, creating the point C |
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| 7. Draw a line from P through C, and on a little more. The end of this line is point R |
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| 8. Done. The angle ∠QPR has a measure of 45° |
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