Canadians are not doing well at this!

This puzzle was posted online and quickly went viral due to the amount of debate over the correct answer.

How many triangles are there in the following image?


This is not just a test of observation skills. The problem appears to be a common test question worldwide.

And there is actually a nice mathematical counting trick.

Can you figure it out?

Check out the video for a solution. Or scroll down for the answer


One method to solve the problem is to count all the triangles.

There are 18 as illustrated here:

The problem with counting is you have to work it out on every variation. Like what if we added one more vertical line? Or one more horizontal line? There would be no way a student could work out every variation in an exam under time constraints.

What makes the problem interesting is there is actually a systematic way to count from a mathematical pattern.


Did you get it correct?

Only 2% of people do first time!