David uses some coins to form a triangle. There is a coin at every corner. How many coins does he use if there are 6 coins on each side of the triangle?
David uses some coins to form a triangle. There is a coin at every corner. How many coins does he use if there are 6 coins on each side of the triangle?
Draw it and count them. I don't know if you mean a solid triangle or just the outline.
If you mean just the outline, you could get yourself 15 coins and make a model. :D
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