Operation order giving different results

Question

When solving the shape challenge in Java, I couldn't figure out why my code was not passing test case number 3 (locked).
Turns out the problem was that for my calculation of the area of the circle I was using width*width*Math.PI instead of Math.PI*width*width.
Changing the order fixed the problem. But why?!
As far as I understand, the order of factors shouldn't change the result of a multiplication.
Is this some kind of expected behavior with Math.PI, or some kind of bug?

https://code.sololearn.com/cva0my76wT1A/?ref=app

Answer 1

i checked the output in java for 3 different sequences of the multiplication like done by Leandro, and the result was all the same. but 1 of my 5 trials was timed out, so may be it is an issue of the server.
But in general the sequence of operands with a multiplication does not affect the result.

Answer 2

Can you save your code on SL Playground and link here for posibility to help.

Answer 3

Edited with the code that caused the error and the challenge description.

I'm pretty sure Lothar is correct, it must have been a time out issue.

Thank you all very much!

Answer 4

I‘m not sure yet but we are in digital world. That means there can be a difference when the operation at the beginning convert integer to double or at the last multiplication. Maby calculating on PC with another compiler can be answer this.