Definition:Complete Quadrangle/Diagonal Point

Definition

Let $A$, $B$, $C$ and $D$ be the points of a complete quadrangle $ABCD$.

The diagonal points of $ABCD$ are the points of intersection of the lines:

$AB$ and $CD$

$AC$ and $BD$

$AD$ and $BC$.

Also see

• Results about diagonal points can be found here.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): diagonal point
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): quadrangle
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): diagonal point
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): quadrangle