Try it Given: ABCD is a parallelogram.
Prove: mzA + 2B + m2C + m2D = 360°
D
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By the definition of a parallelogram, AD BC and
AB||DC. Using, AD as a transversal, ZA and 4
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same-side interior angles, so they are
By the definition of supplementary,
MZA+ m2D = 180. Using side vas a transversal,
ZB and C are same-side interior angles, so they are
supplementary. By the definition of supplementary,
m2B + m2 = 180. So, mzA + m2D + m2B + m2 =
180 + 180 by the
M property. Simplifying,
we have m A+ m2B + m2 + m2D = 360°.
A
B
1) Intro
Done
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