গরুর ঘাস খাওয়া | Math Problem

Click here to read the complete problem statement.

How to approach solving this problem?
Any hint?

There will be create a equilateral triangle

there is a problem with the english statement.

In the bangla statement, it says (aπ + b√3 ) over 3
But the english statement says (aπ + b√4 ) over 3
the english statement is wrong as the final does not have √4