搜索
1. 已知线段$d是线段a$、$b$、$c$的第四比例项,其中$a = 2cm$,$b = 4cm$,$c = 5cm$,则$d = $【
A.$1cm$
B.$\frac{5}{2}cm$
C.$10cm$
D.$\frac{8}{5}cm$
C
】A.$1cm$
B.$\frac{5}{2}cm$
C.$10cm$
D.$\frac{8}{5}cm$
答案：
C
2. 下列四组条件中,能识别$\triangle ABC与\triangle DEF$相似的是【
A.$\angle A = 45^{\circ}$,$\angle B = 55^{\circ}$；$\angle D = 45^{\circ}$,$\angle F = 75^{\circ}$
B.$AB = 5$,$BC = 4$,$\angle A = 45^{\circ}$；$DE = 5$,$EF = 4$,$\angle D = 45^{\circ}$
C.$AB = 6$,$BC = 5$,$\angle B = 40^{\circ}$；$DE = 5$,$EF = 6$,$\angle E = 40^{\circ}$
D.$AB = BC$,$\angle A = 50^{\circ}$；$DE = EF$,$\angle E = 50^{\circ}$
C
】A.$\angle A = 45^{\circ}$,$\angle B = 55^{\circ}$；$\angle D = 45^{\circ}$,$\angle F = 75^{\circ}$
B.$AB = 5$,$BC = 4$,$\angle A = 45^{\circ}$；$DE = 5$,$EF = 4$,$\angle D = 45^{\circ}$
C.$AB = 6$,$BC = 5$,$\angle B = 40^{\circ}$；$DE = 5$,$EF = 6$,$\angle E = 40^{\circ}$
D.$AB = BC$,$\angle A = 50^{\circ}$；$DE = EF$,$\angle E = 50^{\circ}$
答案：
C
3. 如图,已知$DE// BC$,$AC = 14$,$AB = 18$,$AD = 10$,则$AE$的长为【
A.$\frac{9}{70}$
B.$\frac{70}{9}$
C.$\frac{5}{126}$
D.$\frac{126}{5}$
B
】A.$\frac{9}{70}$
B.$\frac{70}{9}$
C.$\frac{5}{126}$
D.$\frac{126}{5}$
答案：
B
4. 将点$P(-3,y)向右平移2个单位长度后得到点P'(x,-1)$,则【
A.$x = -3$,$y = -1$
B.$x = -3$,$y = 1$
C.$x = -1$,$y = -3$
D.$x = -1$,$y = -1$
D
】A.$x = -3$,$y = -1$
B.$x = -3$,$y = 1$
C.$x = -1$,$y = -3$
D.$x = -1$,$y = -1$
答案：
D
5. 下列说法正确的是【
A.对应边都成比例的多边形相似
B.对应角都相等的多边形相似
C.边数相同的正多边形相似
D.矩形都相似
C
】A.对应边都成比例的多边形相似
B.对应角都相等的多边形相似
C.边数相同的正多边形相似
D.矩形都相似
答案：
C
6. 如图,在$\triangle ABC$中,$AB = 3AD$,$DE// BC$,$EF// AB$。若$AB = 9$,$DE = 2$,则线段$FC$的长度是【
A.$6$
B.$5$
C.$4$
D.$3$
C
】A.$6$
B.$5$
C.$4$
D.$3$
答案：
C
查看更多完整答案，请扫码查看
