The neusis construction (from Greek νεῦσις from νεύειν "neuein" "incline towards"; plural: νεύσεις "neuseis") fits a line element of given length ("a") in between two given lines ("l" and "m"), in such a way that the line element, or its extension, passes through a given point "P". That is, one end of the line element has to lie on "l", the other end on "m", while the line element is "inclined" towards "P".