A:流弊羡妒轻鸢剪掠合盘托出
B:因缘叫嚣仗义执言耳根清净
C:玩索坍缩逍遥林下高朋满坐
D:洗练颦蹙叨赔鲤对细水常流
如图为某花的结构示意图,对该图描述正确的是( )
已知a,b,c分别是△ABC内角A,B,C的对边,sin2B=2sinAsinC.
(Ⅰ)若a=b,求cosB;
(Ⅱ)设B=90°,且a=2,求△ABC的面积.
—Are those his books?
—Yes, __________.