You made a regular triangle using ribbon with a side length of 20/9 centimeters (cm). If you unroll this ribbon to make a regular pentagon, find how many centimeters (cm) the length of one side is.
20/9 3 [OP_MUL] 5 [OP_DIV]
var_a = 2.2222222222222223
var_b = 3
var_c = var_a * var_b
var_d = 5
var_e = var_c / var_d
print('{:.2f}'.format(round(var_e+1e-10,2)))