DMIC math problem solving

On Tuesday we did DMIC problem solving. We had to solve who is right and wrong. Peter makes different rectangles with a 30cm string, Peter thinks that all the rectangles he makes will have the same area but Miri disagrees, and we think that Peter is correct because all the rectangles he makes has the same length so we think that Peter was correct. but another group said that Peter was wrong, and Miri was correct, the other group cut out some paper and they all have the same length but they are different when they compared one with the other one and realized that they did not have the some area. When I was looking at their way of solving it I just realized that I was wrong because I was not looking at it properly.