如圖,在直角坐標(biāo)系中,Rt△AOB的兩條直角邊OA,OB分別在x軸的負(fù)半軸,y軸的負(fù)半軸上,
![](http://hiphotos.baidu.com/zhidao/pic/item/377adab44aed2e73bea66b9e8401a18b87d6fa31.jpg)
且OA=2,OB=1.將Rt△AOB繞點(diǎn)O按順時(shí)針?lè)较蛐D(zhuǎn)90°,再把所得的像沿x軸正方向平移1個(gè)單位,得△CDO.
(1)寫(xiě)出點(diǎn)A,C的坐標(biāo);
(2)求點(diǎn)A和點(diǎn)C之間的距離.
![](http://hiphotos.baidu.com/zhidao/pic/item/5d6034a85edf8db1086191d60a23dd54564e7431.jpg)
(1)點(diǎn)A的坐標(biāo)是(-2,0),點(diǎn)C的坐標(biāo)是(1,2).
(2)連接AC,在Rt△ACD中,AD=OA+OD=3,CD=2,
∴AC
2=CD
2+AD
2=2
2+3
2=13,
∴AC=
.