MathDB

5

Part of 2010 South africa National Olympiad

Problems(1)

Lines intersecting at some angle alpha

Source: South African MO 2010 Q5

5/26/2012
(a) A set of lines is drawn in the plane in such a way that they create more than 2010 intersections at a particular angle α\alpha. Determine the smallest number of lines for which this is possible.
(b) Determine the smallest number of lines for which it is possible to obtain exactly 2010 such intersections.
geometry unsolvedgeometry