15 lines.
There are 91 lines.
3 lines and one plane
Through any two distinct points, exactly one line can be drawn. For 5 non-collinear points, each pair of points can form a line. The number of ways to choose 2 points from 5 is given by the combination formula ( \binom{5}{2} ), which equals 10. Therefore, 10 lines can be drawn through 5 non-collinear points.
10 lines, but only if no three of them are collinear.
Yes. You can draw infinitely many straight lines from each point.
Through any two distinct points, exactly one straight line can be drawn. If you have more than two points, the number of lines that can be drawn depends on how many of those points are distinct and not collinear. For ( n ) distinct points, the maximum number of lines that can be formed is given by the combination formula ( \binom{n}{2} ), which represents the number of ways to choose 2 points from ( n ). If some points are collinear, the number of unique lines will be less.
From 8 non-collinear points, the number of straight lines that can be drawn is determined by choosing any two points to form a line. This can be calculated using the combination formula ( \binom{n}{r} ), where ( n ) is the total number of points and ( r ) is the number of points to choose. For 8 points, the calculation is ( \binom{8}{2} = \frac{8 \times 7}{2 \times 1} = 28 ). Therefore, 28 straight lines can be drawn using 8 non-collinear points.
Not sure about complanar. Coplanar lines can be collinear but need not be.
Three
3
depends on the position of the points if points are collinear, we have just only one line, the minimum number. If points are in different position (if any of the two points are not collinear) we have 21 lines (7C2), the maximum number of lines.
Any three non-collinear points will define a single plane. A plane is composed of an infinite number of distinct lines.