Warm­up:
1. Q is obtuse.
a) What are the limitations on m Q?
b) What are the restrictions on 2. Given that R is a right angle, solve for x?
Q
x.
R
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More Definitions!
A point is the midpoint of a line segment iff it divides the line segment into two equal segments.
Angle Bisector:
A line bisects an angle iff it divides the angle into two equal angles.
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Corollary:
A theorem that can be easily proved as a consequence of a postulate or another theorem.
Corollary to the Ruler Postulate:
A line segment has exactly one midpoint.
Corollary to the Protractor Postulate:
An angle has exactly one ray that bisects it.
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In the acetylene molecule, AB=CD, A­B­C, and B­C­D. Use these facts to prove that AC=BD.
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Use the additional fact that AC > 2AB to indirectly prove that B is not the midpoint of AC.
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