oblique strophoid

oblique strophoid

[ə′blēk ′strō‚fȯid]
(mathematics)
A plane curve derived from a straight line L and two points called the pole and the fixed point, where the fixed point lies on L but is not the foot of the perpendicular from the pole to the line; it consists of the locus of points on a rotating line L ′ passing through the pole whose distance from the intersection of L and L ′ is equal to the distance of this intersection from the fixed point.