N is the amount of sides
sum=13 times 180 =2340
Use formula a squared equals to c squared minus b squared
40^2-24^2 is 1024
Square root of 1024 is 32.0
Converting to base 10 can be done easily by writing a sort of digit expansion. In base 6, this number literally means

Simplifying this gives the value in base 10.

Explanation:
Kadisha's method works because 15% is 3 times 5%, and both amounts are computed on the amount of the bill before tax is added.