relationship between triangle and golden ratio

[todd098]

I am having trouble finding the relationship between a 72-72-36 triangle and the golden ratio. Could someone point me in the right direction or explain it? Thanks

[ahrkron]

Since 72 = 360/5, that triangle should be related to a pentagon, and I think the sides and the diagonals from pentagons are related by the golden ratio. I'm talking from memory, though, but it should be easy to check.

[uart]

I am having trouble finding the relationship between a 72-72-36 triangle and the golden ratio. Could someone point me in the right direction or explain it? Thanks

Did you ever consider looking at the ratio of the long sides to the short side of that triangle. Use the sine rule and I'm sure you'll find it easy enough.

[Gokul43201]

Notice that 2 sin(Pi/10) = golden ratio