81 is 45% of 180.
Simply multiply the percentage rate to the whole to get the part it is representing.
180 is the whole or 100%
45% is the percentage rate of the part.
180 x 45% = 81
81 is the value of the part
Assuming the part and the whole is given, to get the percentage rate, simply divide the part by the whole. and multiply its quotient by 100%.
81/180 = 0.45 x 100% = 45%
In the instance that the part and its corresponding percentage rate is given, find the whole. divide the part by its percentage rate.
81/45% or 81/0.45 = 180