have a look at the short paper attached.

The number of the equal triangles should be 1+n/(n/2), if n=10, it is 55.

Of you also count those up side down equal triangles, it should be n^2, if n = 10, it is 100.

Then what is the author talking about?

Edited June 24, 20223 yr by PeterBushMan

2 hours ago, PeterBushMan said:

The number of the equal triangles should be 1+n/(n/2), if n=10, it is 55.

...

Then what is the author talking about?

What are you talking about ?

[math]1 + n/\left( {n/2} \right) = 1 + n \times \frac{2}{n} = 1 + 2 = 3[/math]