题目内容
(本题满分9分)如图,在
中,
,
,把边长分别为
的
个正方形依次放入
中,请回答下列问题:
(1)按要求填表![]()
(2)第
个正方形的边长
;
(3)若
是正整数,且
,试判断
的关系.![]()
(1)
·············································································· 6分
(2)
.························································································· 8分
(3)![]()
····································································· 10分
.·············································································· 11分
.·················································································· 12分
解析
.(本题满分5分)如图一根木棒放在数轴上,木棒的左端与数轴上的点A重合,右端与点B重合.
1.若将木棒沿数轴向右水平移动,则当它的左端移动到B点时,它的右端在数轴上所对应的数为20;若将木棒沿数轴向左水平移动,则当它的右端移动到A点时,则它的左端在数轴上所对应的数为5(单位:cm),由此可得到木棒长为 cm.
2.由题(1)的启发,请你借助“数轴”这个工具帮助小红解决下列问题:
问题:一天,小红去问曾当过数学老师现在退休在家的爷爷的年龄,爷爷说:“我若是你现在这么大,你还要40年才出生;你若是我现在这么大,我已经125岁,是老寿星了,哈哈!”,请求出爷爷现在多少岁了?