Puzzler!

[BadPoison]

I find this answer to be unsatisfying:
[spoiler:85jx4qg8]http://puzzles.nigelcoldwell.co.uk/twenty.htm
Is this the "real" answer? When I printed it out there was no noticeable difference in angle --- the two triangles still lined up on each other.[/spoiler:85jx4qg8]
Is there a better solution than this?

[pedricero matao]

I wish i didn't already know the answer to this. I love puzzles which truly squeeze my brain.  :bananacolor:

Hmmmmmmm. Still thinking

Take a look at the hypotenuse (the longest side).

[McQ]

Wait a minute! You mean [spoiler:3g776jlv]the freaking hypotenuse isn't a straight line in either one?  :crazy:

Foul![/spoiler:3g776jlv]

[BadPoison]

Wait a minute! You mean [spoiler:16yvwlk0]the freaking hypotenuse isn't a straight line in either one?  :crazy:

Foul![/spoiler:16yvwlk0]

Exactly my thoughts. Lame.
[spoiler:16yvwlk0]Because I totally printed it out and cut it out to layer on top of each other. I really couldn't see it not being a straight line...[/spoiler:16yvwlk0]

[quizlixx]

[spoiler:pdzdpf8v]my comment is in the spoiler below[/spoiler:pdzdpf8v]
[spoiler:pdzdpf8v]I can't figure it out!  [/spoiler:pdzdpf8v]

[pedricero matao]

major spoiler here
[spoiler:1gpwrhc3]Just check the slopes in the triangles.
We can do that seeing if the angles which are to the left (the most acute angles) are the same, just calculate the tangent. They are similar (thus and changing the color and size of each one gives the appearance to be equal), but they aren't equal. So if you just have 2 different angles and put them together as in the figure, the resulting line will not be a straight line, making the figure to be a quadrilateral, not a big triangle. The difference between the slighest convex polygon and the concave one sums that area which appears to be missing.

Being the difference so small between the two angles (~1,2º) this is not well perceived if you just measure them, unless maybe if you make it real big. But if you do the math, you can see it clearly.

Or so I think.
Sorry about the crappy English...

PS: I guess you aren't de coña,    but yeah it can be tought of as an optical illusion. But it's plain Euclidean geometry, squares and triangles you know[/spoiler:1gpwrhc3]

[JillSwift]

Don't spoil it if you're still working on it.  [/spoiler:28kl7e82]

[Sophus]

I think that's why I don't understand these types of things..... they're all trick questions. The question almost always asserts a lie.  

Are there any more like these?

[AlP]

I just figured it out.

[spoiler:132ib05r]The red and turquoise triangles are not similar. Therefore the composite "triangle" is not a triangle. Abandon math. Lol.[/spoiler:132ib05r]

[pedricero matao]

I think that's why I don't understand these types of things..... they're all trick questions. The question almost always asserts a lie.  

Are there any more like these?

No, this is not tricky! It's tricky if you trust what apparently you see with your eyes, but doing some simple calculations lets you find the answer easily

[HandsandDreams]

I enjoyed that!  Thank you.  Got it on my own, but it took a while.  The hint about looking at the hypotenuse helped me.

[spoiler:1673hp46]If you look closely at the lower diagram, where the two triangles meet, you can't see the corner.  But if you follow that vertical line straight up to the top diagram, you CAN see the corner, proving the two smaller triangles are not similar triangles.[/spoiler:1673hp46]

[joeactor]

Ok... How about a math based one?

This one's easy, but a little deceptive as well.

Three friends eat at a restaurant and agree to split the bill of $30 evenly.
Each pays $10.
The waiter comes back and tells them the manager is running a special.
Dinner will only be $25 tonight, so he give them $5 back
Since they wanted to split evenly, each takes a dollar, and they tip the waiter $2.

...So, each man paid $9 for his dinner.
$9 times 3 friends equals $27, plus the $2 from the waiter equals $29.

Where's the extra dollar?

JoeActor
(no, I didn't keep the dollar!)

[BadPoison]

Ok... How about a math based one?

This one's easy, but a little deceptive as well.

Three friends eat at a restaurant and agree to split the bill of $30 evenly.
Each pays $10.
The waiter comes back and tells them the manager is running a special.
Dinner will only be $25 tonight, so he give them $5 back
Since they wanted to split evenly, each takes a dollar, and they tip the waiter $2.

...So, each man paid $9 for his dinner.
$9 times 3 friends equals $27, plus the $2 from the waiter equals $29.

Where's the extra dollar?

JoeActor
(no, I didn't keep the dollar!)

[spoiler:2d6ohme6]$9 times 3 friends equals $27. The $2 tip is included in the $27 so you would just add the $3 of change received to get the original $30.

Yippee![/spoiler:2d6ohme6]

Thanks Joe!

[joeactor]

Got it in 6 minutes, BadPoison - kudos!

[JillSwift]

and they tip the waiter $2.

Cheapskates.
15% tip on $25 is $3.75.