题型:填空题 题类:常考题 难易度:困难
天津市滨海新区2019-2020学年七年级下学期数学期末试卷
如图②所示,将长方形纸片剪两刀,剪出三个角(∠BAE , ∠AEC , ∠ECD),∠BAE+∠AEC +∠ECD=360(度);
⑴如图③所示,将长方形纸片剪三刀,剪出四个角(∠BAE , ∠AEF , ∠EFC , ∠FCD), 则∠BAE+∠AEF+∠EFC+∠FCD=(度);
⑵如图④所示,将长方形纸片剪四刀,剪出五个角(∠BAE , ∠AEF , ∠EFG , ∠FGC , ∠GCD), 则∠BAE+∠AEF+∠EFG+∠FGC+∠GCD=(度);
⑶根据前面的探索规律,将本题按照上述剪法剪n刀,剪出n+1个角,那么这n+1个角的和是(度).
序号 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
… |
n |
A组 |
3 |
5 |
7 |
9 |
11 |
13 |
15 |
… |
______ |
B组 |
5 |
8 |
13 |
20 |
29 |
40 |
______ |
… |
n2+4 |
C组 |
4 |
8 |
16 |
32 |
64 |
128 |
256 |
… |
______ |
试题篮