How many lines can be formed from 17 points
where no 3 points are collinear?
n(n + 1) | |
2 |
P1,P2,P3,P4,P5,P6,P7,P8,P9,P10,P11,P12,P13,P14,P15,P16,P17
P1 can be uniquely paired into the following 16 points:
(P1,P2),(P1,P3),(P1,P4),(P1,P5),(P1,P6),(P1,P7),(P1,P8),(P1,P9),(P1,P10),(P1,P11),(P1,P12),(P1,P13),(P1,P14),(P1,P15),(P1,P16),(P1,P17)
P2 can be uniquely paired into the following 15 points:
(P2,P3),(P2,P4),(P2,P5),(P2,P6),(P2,P7),(P2,P8),(P2,P9),(P2,P10),(P2,P11),(P2,P12),(P2,P13),(P2,P14),(P2,P15),(P2,P16),(P2,P17)
P3 can be uniquely paired into the following 14 points:
(P3,P4),(P3,P5),(P3,P6),(P3,P7),(P3,P8),(P3,P9),(P3,P10),(P3,P11),(P3,P12),(P3,P13),(P3,P14),(P3,P15),(P3,P16),(P3,P17)
P4 can be uniquely paired into the following 13 points:
(P4,P5),(P4,P6),(P4,P7),(P4,P8),(P4,P9),(P4,P10),(P4,P11),(P4,P12),(P4,P13),(P4,P14),(P4,P15),(P4,P16),(P4,P17)
P5 can be uniquely paired into the following 12 points:
(P5,P6),(P5,P7),(P5,P8),(P5,P9),(P5,P10),(P5,P11),(P5,P12),(P5,P13),(P5,P14),(P5,P15),(P5,P16),(P5,P17)
P6 can be uniquely paired into the following 11 points:
(P6,P7),(P6,P8),(P6,P9),(P6,P10),(P6,P11),(P6,P12),(P6,P13),(P6,P14),(P6,P15),(P6,P16),(P6,P17)
P7 can be uniquely paired into the following 10 points:
(P7,P8),(P7,P9),(P7,P10),(P7,P11),(P7,P12),(P7,P13),(P7,P14),(P7,P15),(P7,P16),(P7,P17)
P8 can be uniquely paired into the following 9 points:
(P8,P9),(P8,P10),(P8,P11),(P8,P12),(P8,P13),(P8,P14),(P8,P15),(P8,P16),(P8,P17)
P9 can be uniquely paired into the following 8 points:
(P9,P10),(P9,P11),(P9,P12),(P9,P13),(P9,P14),(P9,P15),(P9,P16),(P9,P17)
P10 can be uniquely paired into the following 7 points:
(P10,P11),(P10,P12),(P10,P13),(P10,P14),(P10,P15),(P10,P16),(P10,P17)
P11 can be uniquely paired into the following 6 points:
(P11,P12),(P11,P13),(P11,P14),(P11,P15),(P11,P16),(P11,P17)
P12 can be uniquely paired into the following 5 points:
(P12,P13),(P12,P14),(P12,P15),(P12,P16),(P12,P17)
P13 can be uniquely paired into the following 4 points:
(P13,P14),(P13,P15),(P13,P16),(P13,P17)
P14 can be uniquely paired into the following 3 points:
(P14,P15),(P14,P16),(P14,P17)
P15 can be uniquely paired into the following 2 points:
(P15,P16),(P15,P17)
P16 can be uniquely paired into the following 1 points:
(P16,P17)
16 + 15 + 14 + 13 + 12 + 11 + 10 + 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1
17(17 - 1) | |
2 |
17(16) | |
2 |
272 | |
2 |