the mere fact that the los-thickness increases by angling the plate is not however the motive for applying sloped armour in armoured vehicle design. the reason for this is that this increase offers no weight benefit. to maintain a given mass of a vehicle, the area density would have to remain equal and this implies that the los-thickness would also have to remain constant while the slope increases, which again implies that the normal thickness decreases. in other words: to avoid increasing the weight of the vehicle, plates have to get proportionally thinner while their slope increases, a process equivalent to shearing the mass.