问题 填空题 已知△ABC∽△A1B1C1,AB:A1B1=2:3,则S△ABC与S△A1B1C1之比为______. 答案 ∵△ABC∽△A1B1C1,AB:A1B1=2:3,∴S△ABC:S△A1 B1C1=2:9.故填:2:9.