sin0°=0, cos0°=1, tan0°=0.sin30°=1/2, cos30°=√3/2, tan30°=√3/3.sin45°√2/2, cos45°√2/2, tan45°=1.sib60°=√3/2, cos60°=1/2, tan60°=√3.sin90°=1, cos90°=0, tan90°不存在.
