plane geometry

geometry of two-dimensional or plane figures 平面几何学.

plaid, plain, plain clothes (esp of police officers), plain dealing, plain flour, plain-clothes man, plain-spoken, plainchant, plainly, plainness, plains, plainsman, plaint, plaintiff, plaintive, plaintively, plaintiveness, plait, plan, plane, plane sailing, plane-table, planet, planetarium, planetary, plangency, plangent, plangently, plank, planking, plankton, planned, planning, plant, plantain, plantation, planter, plaque, plasma, plaster,