If I asked you to draw five non-overlapping triangles by using five straight lines, then obviously a five-pointed star would fit the bill - and a further two triangles could be achieved by inserting another short horizontal line, as shown in the diagram above.
These two amounts, five and seven, are the theoretical maximums available with five and six lines. Obviously, the maximums from three lines and four lines respectively will be one and two triangles.
This week's problem is much more difficult. Can you produce 11 non-overlapping triangles using seven straight lines?
See the solution to the triangles puzzle.
This was first published in April 2008