解答:解:∵设圆柱的底面直径为10,截面与底面成60°∴椭圆的短轴长2b=10,即b=5,椭圆的长轴长2a= 10 cos60° =20,即a=10,根据:c= a2?b2 =5 3 ,则椭圆的离心率e= c a = 3 2 ,故答案为:20,10, 3 2