T H E E L E M E N T S |
Book III Proposition 18 | |
For, if not, let FG be drawn from F perpendicular to DE. Then, since the angle FGC is right, the angle FCG is acute; [I.17] and the greater angle is subtended by the greater side; [I.19] therefore FC is greater than FG. But FB is equal to FC; therefore FB is also greater than FG, |
||
Previous Page Return to Propositions Next Page |