a ship sails from a point at a distance of 4 km and a bearing of 40 degree noth of east relative to a lighthouse to a point 6 km from the lighthouse at 60 degree north to west.

Question

a ship sails from a point at a distance of 4 km and a bearing of 40 degree noth of east relative to a lighthouse to a point 6 km from the lighthouse at 60 degree north to west.
calculate
a) the displacement
b)the least distance between them