Name _______________________________________________
Date_________________________________________________
Topic
DO NOW: Find the m<a (measure of angle a). Justify your answer using a complete
sentence.
Notes
Vocabulary:
1) Substitution Property- if x = y, then x can be substituted in for y in any
equation and y can be substituted in for x in any equation.
2) Subtraction Property- when both sides of an equation have the same
number or variable subtracted from them, the remaining expressions are still
equal.
3) Addition Property- allows you to add two quantities set equal to each other
and set the answers equal to each other.
4) Perpendicular Lines- two intersecting line that for 90 degree angles
5) Parallel Lines- two lines that never intersect each other. Parallel lines cut
by a transversal form alternate interior and exterior angles, corresponding
angles, and consecutive (same-side) interior angles.
I DO
Writing Proofs:
Given the labeled diagram can we prove that x + y = z?
Statement
1.
Reason
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We DO
Given the diagram prove that vertical angles w and y are congruent.
Statement
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Reason
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YOU DO 1:
Given the diagram prove that m<w + m<x + m<z = 180. Make a plan first. What do
you know about <x, <y, and <z?
Statement
1.
Reason
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4.
YOU DO 2:
Given the diagram prove that m< w = m< y + m< z. Hint: What is the relationship
between <w, <x and <z?
Statement
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Reason
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YOU DO 3:
Given the diagram prove that <y + <z = <w + <x. Hint: How many triangles do you se
and what do we know about the angles of a triangle?
Statement
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Reason
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YOU DO 4:
In the figure to below, AB  CD and BC  DE. Prove that m∠ABC = m∠CDE.
Statement
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Reason
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WE DO 2:
In the figure to below, prove that the sum of the angles marked by arrows is 900°.
(You will need to write in several labels into the diagram for this proof.)
Statement
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Reason
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YOU DO 5:
In the figure to below, prove that DC  EF.
Statement
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EXIT TICKET
In the diagram below prove that the sum of the labeled angles is 1800
STATEMENT
1.
REASON