Keyerror While Perfoming Solve Of Two Equation

1st i need to get two equation of two longest line length i put lenghths with eq in list like these [( length 1 , eq 1 ) ,.....] sort list with reverse get two equation of two lo

Solution 1:

If you print out the equations you are trying to solve you will see that they are the same so the only solution returned is {z:t} not {z:smthng, t:smthngelse}. So when you request the value of t it tells you that there is no t in the solution dictionary. Now you have to go back and see that you properly computed that equations that were to be solved.

Note, too, that SymPy has the Polygon/Triangle objects and might already have a method to answer the question that you are asking.