T
H
E

E
L
E
M
E
N
T
S
Book I   Proposition 34
For, since
    AB is parallel to CD, and the straight line BC has fallen upon them,
    the alternate angles ABC, BCD are equal to one another. [I.29]

Again, since
    AC is parallel to BD, and the straight line CB has fallen upon them,
    the alternate angles ACB, CBD are equal to one another. [I.29]
Previous Page    Return to Propositions    Next Page