T H E E L E M E N T S |
Book III Proposition 4 | |
Then, since a straight line FE through the center bisects a straight line AC not through the center, it also cuts it at right angles; [III.3] therefore the angle FEA is right. Again, since a straight line FE bisects a straight line BD, it also cuts it at right angles; [III.3] therefore the angle FEB is right. |
||
Previous Page Return to Propositions Next Page |