Can you take ten points, forming the vertices of five convex quadrilaterals in three dimensions, such that every quadrilateral intersects each of the other four at a vertex? Solution
Are you saying that each pair of quadrilaterals intersect at a mutual vertex and nowhere else, and that each vertex is common to exactly two quadrilaterals?
Are you saying that each pair of quadrilaterals intersect at a mutual vertex and nowhere else, and that each vertex is common to exactly two quadrilaterals?
Here is another puzzle.
Can you take ten points, forming the vertices of five convex quadrilaterals in three dimensions, such that every quadrilateral intersects each of the other four at a vertex? Solution
The problem is confusing.
Are you saying that each pair of quadrilaterals intersect at a mutual vertex and nowhere else, and that each vertex is common to exactly two quadrilaterals?
Yes, exactly.
I got it. Nice.