# Ceva's theorem

If points $P, Q$ and $R$ are on the sides $BC, CA$ and $AB$ of a triangle then the lines $AP, BQ$ and $CR$ are concurrent if and only if the product of the ratios

$\Large \frac {BP}{PC}.\frac {CQ}{QA}.\frac {AR}{RB}$ is +1

If points $P, Q$ and $R$ are on the sides $BC, CA$ and $AB$ of a triangle then the lines $AP, BQ$ and $CR$ are concurrent if and only if the product of the ratios

$\Large \frac {BP}{PC}.\frac {CQ}{QA}.\frac {AR}{RB}$ is +1