由题知A1D1=C1D1=5 ∠A1D1C1=120° 过点D1作A1C1的垂线,D1M ,又∠D1C1A1=30°
所以C1答案知道，就过程不清楚！！！5根号7，5根号5由题知A1D1=C1D1=5∠A1D1C1=120°过点D1作A1C1的垂线，D1M ，又∠D1C1A1=30°所以C1 M=(5√5)/2所以A1C1=5√5同理BD=AC=B1D1=5√5又因为CC1=10∠CC1A1=90°由勾股定理得 A1C²=CC1²+A1C1²将数据代入计算得A1C²=175故A1C=5√7你的题有错