“Between 50 and 60 is a mistake, there are no nine but eleven lines.” Lonneke van Krimpen was working on a maths sum when she needed exactly that piece of her geo-triangle. “Then I saw that it was not right.”

Lonneke discovered the printing errors on the HEMA's triangle. At first she doubted herself, but after counting and inquiring with friends, she realized that it was indeed not good.

We visited her home, to discuss the triangular method to the millimeter:

Through the internet she contacted with the HEMA, especially to help others. “I was afraid it might otherwise go wrong for other students.” And the HEMA reacted: she could bring back her geo-triangle. Later, the company announced that all the wrong triangles were removed from the market.

But that does not seem to have happened everywhere. “We were at the HEMA this afternoon and then of course I looked at the shelf of the triangles.” Sure enough, she still found triangles with wrong lines. “I really thought: eh, why is this not yet gone?”

The exam period starts Monday. Lonneke also has to go to the box. She is good for mathematics: a 7.7. “The chance that I will not succeed due to this misprint is small.” But she should not think that she would start her mathematics exam with her wrong method. “You do not know in advance what will happen in the exam, if I had just needed that piece, then I think I would have been in trouble.”