∴S1=
1 |
2 |
1 |
2 |
1 |
2 |
1 |
4 |
S△B1C1M2=
1 |
2 |
1 |
2 |
3 |
2 |
3 |
4 |
S△B1C1M3=
1 |
2 |
1 |
2 |
5 |
2 |
5 |
4 |
S△B1C1M4=
1 |
2 |
1 |
2 |
7 |
2 |
7 |
4 |
S△B1C1Mn=
1 |
2 |
1 |
2 |
2n?1 |
2 |
2n?1 |
4 |
∵BnCn∥B1C1,
∴△BnCnMn∽△B1C1Mn,
∴S△BnCnMn:S△B1C1Mn=(
BnMn |
B1Mn |
| ||
|
即Sn:
2n?1 |
4 |
1 |
(2n?1) |
1 |
2 |
1 |
2 |
1 |
2 |
1 |
4 |
1 |
2 |
1 |
2 |
3 |
2 |
3 |
4 |
1 |
2 |
1 |
2 |
5 |
2 |
5 |
4 |
1 |
2 |
1 |
2 |
7 |
2 |
7 |
4 |
1 |
2 |
1 |
2 |
2n?1 |
2 |
2n?1 |
4 |
BnMn |
B1Mn |
| ||
|
2n?1 |
4 |
1 |
(2n?1) |