Friday Puzzler -- Triangles

Re: Friday Puzzler -- Triangles

Alex Y

Just saw that the picture got slightly truncated. The edge of the picture is NOT a side of any triangles. Just the triangles formed by the lines in the picture.

Re: Friday Puzzler -- Triangles

Kent B

Pass. Seen it. Obi-Wan Larry can have this one.

Re: Friday Puzzler -- Triangles

Larry Barrett

I've seen it. too.

Re: Friday Puzzler -- Triangles

Alex Y

You guys are no fun!

Amazing how hard it is to count them, even though it is not a large number. I just trust the math!

Re: Friday Puzzler -- Triangles

Henry Higginbotham

I find 14. Based on my prior performance on similar find-the-shapes puzzles, there are likely closer to 28.

Re: Friday Puzzler -- Triangles

Alex Y

14 is closer to the answer than is 28.

But there are more to find.

Re: Friday Puzzler -- Triangles

Sam Force

Ill try 18

Getting Closer!

Kent or Larry

Alex Y

One of you want to reveal how to tell how many triangles there are without counting any higher than six?

Re: Kent or Larry

Larry Barrett

If I recall the problem/answer correctly it went this way. Every triangle has three sides. There are six lines in this problem and each of the six lines crosses all of the other five lines. So the number of triangles is just the number of combinations of three lines out of the total number of lines - six. This is given by 6!/3!x3! =

6x5x4/3x2x1 = 20.

Re: Kent or Larry

Alex Y

Correct!

Happy to help