Four Way Dissections
Author : Gavin Theobald
{3}-{4}-{6}-{8}
Triangle — Square — Hexagon — Octagon
{3}-{4}-{6}-{12}
Triangle — Square — Hexagon — Dodecagon
{3}-{4}-{6}-{6/2}
Triangle — Square — Hexagon — Hexagram
{3}-{4}-{8}-{6/2} 
Triangle — Square — Octagon — Hexagram
There is a very large number of possible four way dissections that can be performed. To limit this number I have restricted myself to looking for four way dissections of the regular polygons that can be solved in eighteen or fewer pieces.
Triangle — Square — Hexagon — Octagon (18 pieces)
Triangle — Square — Hexagon — Octagon (17 pieces with 2 turned over)
Triangle — Square — Hexagon — Dodecagon (17 pieces with 4 turned over)
Triangle — Square — Hexagon — Hexagram (16 pieces)
Triangle — Square — Octagon — Hexagram (16 pieces)
Triangle — Square — Octagon — Hexagram (15 pieces with 2 turned over)