平行四边形的对角线互相平分,可得:AO = CO ,BO = DO .
已知,AO比AB短3cm,BO比AB长2cm,可得:BO比AO长5cm.
已知,BO是AO的2倍,可设:AO = CO = x ,BO = DO = 2x .
可列方程:2x-x = 5cm ,解得:x = 5cm ;
所以,AC = 2AO = 2x = 10cm ,BD = 2BO = 4x = 20cm .
平行四边形的对角线互相平分,可得:AO = CO ,BO = DO .
已知,AO比AB短3cm,BO比AB长2cm,可得:BO比AO长5cm.
已知,BO是AO的2倍,可设:AO = CO = x ,BO = DO = 2x .
可列方程:2x-x = 5cm ,解得:x = 5cm ;
所以,AC = 2AO = 2x = 10cm ,BD = 2BO = 4x = 20cm .