Crazy Triangle puzzle (in Off-topic)

http://www.begent.net/triangle.htm

This makes no sense to me but then maybe i am over thinking it.

or try this

The trick is that it is not a real triangle

I think the trick is that the gridlines are not the same. If you look at the bottom left corner of the red triangle on the bottom figure, you'll notice it's right on the intersection. In the top triangle, the same point is slightly inside the intersection.

Therefore the bottom figure represents a slightly larger triangle (with a piece missing)

No, the ratio of the red triangle's sides is 3:8 = 0.375, while the dark green triangle's is 2:5 = 0.2. So the red and green triangles are not similar and, therefore, do not have the same gradient. Hold a ruler against the slope of the red triangle and see how the green triangle deviates from this line, the difference in area being one square.