摘要：(1)在平面展开图中可画出最长的线段长为． ················································································· 1分 如图(1)中的.在中 .由勾股定理得: ··············· 3分 答:这样的线段可画4条．····· 4分 (2)立体图中为平面等腰直角三角形的一锐角. ．····················································· 5分 在平面展开图中.连接线段.由勾股定理可得: ．········································· 7分 又. 由勾股定理的逆定理可得为直角三角形． 又. 为等腰直角三角形．······························· 8分 ．·················································· 9分 所以与相等． 10分

网址：http://m.1010jiajiao.com/timu3_id_456870[举报]