Write a paragraph proof of Theorem 3-8: In a plane, if two lines are perpendicular to the same line, then they are parallel to each other.

party.girl286
Nov 2, 2017

#1**+2 **

Here's my best shot

r, t are perpendicular to s __ given__ angle 3 = angle 4 = angle 5 = angle 6 __definition of perpendicular lines__ .....so angle 3 = angle 6 and by Euclid, Book 1, Proposition 27.....

If a straight line falling on two straight lines makes the alternate angles equal to one another, then the straight lines are parallel to one another.

CPhill
Nov 2, 2017