+177 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.
+128408 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.
