## Lucas numbers : legs of a right triangle

Lucas numbers :   $L_{n} \; = \; L_{n-1} \; + \; L_{n-2}$
https://en.wikipedia.org/wiki/Lucas_number

The legs of a right triangle are:

$L_{n-1} \, L_{n+2}$
$2 \, L_{n} \, L_{n+1}$

What feature of the triangle has   $L_{n-1} \, L_{n}$   as its measure?

Note that:

An equation connecting the Fibonacci numbers   $F_{n}$   to the Lucas numbers   $L_{n}$   :

$L_{n} \; = \; F_{n-1} \; + \; F_{n+1}$    for all integers    $n$