homothetic figures
同位相似图形，位似图形

• rotor
• rotor of condenser
• rottenstone
• rouge
• rough air
• rough-annealed glas
• rough blank
• rough-cast glass
• roughened metal plate
• rougher
• rough focusing
• roughing
• roughing machine
• rough material
• roughness
• roughnessmeter
• roughness spectrum
• roughoeter
• rough plan
• rough service lamp
• rough surface
• roulette
• round
• round guide
• rounding error