You figure it out

[Vain]

www.123opticalillusions.com/opt38.htm

[hierachy]

The green triangle has a steeper slope than the red one.

[Loredoctor]

The green triangle has a steeper slope than the red one.

That's not right - they share the same angle.

Edit: I think I've worked it out. It's a play on Pythagoras' Theorem.

[I'm Murrin]

Not quite, Lore. 3:8 and 2:5 aren't on the same scale. 22.6 degrees vs 21.8. Still, I'm not convinced that's the reason.

[Vain]

I think James has a point - the slopes are not the same. But what's your explanation Lore?

[Montresor]

If you stare long enough into the hole in the triangle, the hole in the triangle also stares into you.

[Loredoctor]

Not quite, Lore. 3:8 and 2:5 aren't on the same scale. 22.6 degrees vs 21.8.

Just curious, how did you come to that conclusion that the angles are different? I'm not saying that you are wrong, mind you.

[Loredoctor]

I think James has a point - the slopes are not the same. But what's your explanation Lore?

I'm not really certain.

Edit: The answer is that the triangles aren't the same.

[hierachy]

The green triangle has a steeper slope than the red one.

That's not right - they share the same angle.

...Green triangle has length 5 height 2, red triangle has length 8 height 3

so the green triangle's hypotinuse slopes up by 1 square every 2.5 squares in length.

red triangle slopes up by 1 square every 2.67 sqares in length.

Doesn't sound like the same angle to me...

As a whole, the first shape bows in, the second bows out.

[I'm Murrin]

Not quite, Lore. 3:8 and 2:5 aren't on the same scale. 22.6 degrees vs 21.8.

Just curious, how did you come to that conclusion that the angles are different? I'm not saying that you are wrong, mind you.

When I saw James mention it, I had a closer look, and saw that he was right--if they were the same the red would cross a grid point at 2:5. Counted the squares, then a quick bit of trig gave me the angles (a/b=tanA).

[Loredoctor]

The green triangle has a steeper slope than the red one.

That's not right - they share the same angle.

...Green triangle has length 5 height 2, red triangle has length 8 height 3

so the green triangle's hypotinuse slopes up by 1 square every 2.5 squares in length.

red triangle slopes up by 1 square every 2.67 sqares in length.

Doesn't sound like the same angle to me...

As a whole, the first shape bows in, the second bows out.

For the first one, you're wrong, but the second one - then the red and green triangles diverge slightly.

[Montresor]

I think James has a point - the slopes are not the same. But what's your explanation Lore?

Edit: The answer is that the triangles aren't the same.

I've seen this one before, and Lore's right. I forget the exact details, and maths bores me stiff, but there's a difference in size between the two triangles by about 3% or so (with the bottom one being slightly larger). Primarily, these things are always visual tricks.

[hierachy]

For the first one, you're wrong, but the second one - then the red and green triangles diverge slightly.

Each individual shape is identical from the first to the second.

[Loredoctor]

For the first one, you're wrong, but the second one - then the red and green triangles diverge slightly.

Each individual shape is identical from the first to the second.

The fact is that the second triangle's slope is slightly concave.

[I'm Murrin]

The first is concave, the second is convex. The sum of the two vectors forms the length of what would be the hypotenuse; reversing their order gives the same resultant, but a different path between the points.

[hierachy]

Haha exactly, that's basically what I was getting at with my first post

[Loredoctor]

Haha exactly, that's basically what I was getting at with my first post

In a vague way.

[emotional leper]

It's quite obvious.

A wizard did it.

[Kil Tyme]

Hmm I printed the page, cut the pieces out (just to be sure) and damned they still match one on top the other, even with the extra space. It is a puzzler! I got a headache now.

[The Laughing Man]

just count the bottom squares on each piece. the difference is between 12 and 13. It's the math.

8 + 5

5 + 2 + 5