What are the measurements of a rectangle with a perimeter of 80cms?

to have a perimeter of 80cm the sum of the 4 sides must be 80cm. If it is a rectangle then the sides are unequal and the internal corners are 90 degrees. Adjacent sides have to add up to 40cm and can be any a+b=40 where a does not equal b. 0.1cm and 39.9cm is a valid answerso is 15cm and 25cm - anything that adds up to 40 except 20+20 which would be a square not a rectangle