Perpendicular to Parallels Theorum Proof

Perpendicular to Parallels Theorum: In a plane, if a line is perpendicular to one of two parallel lines, it's perpendicular to the other.

Given: perpendicular to parallel given b c, a b

Statements/Conclusion Justification

1) b c, a b 1) Given

2) 1 is a 90 degree angle. 2) Definition of perpendicular lines

3) 1 is congruent to 2 3) Parallel Lines Postulate

4) m2 = 90 degrees 4) Transitive Property

5) a c 5) Definition of perpendicular lines

Statements/Conclusion	Justification
1) b c, a b	1) Given
2) 1 is a 90 degree angle.	2) Definition of perpendicular lines
3) 1 2	3) Parallel Lines Postulate
4) m2 = 90 degrees	4) Transitive Property
5) a c	5) Definition of perpendicular lines

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