That is not a triangle course !

That is a windward-leeward course with an offset mark to prevent pile ups at the A-mark (windward mark). Without the offset mark there is always some bozo who tacks around A and tries to pull a spi while meeting head on the boats still trying to round the A-mark. Makes for great funniest home-video footage.

Triangle courses see the second mark to lee of the A-mark and at a much greater distance.

Wouter