Question 47614
P=2L+2W OR 420=2L+2(L-4) OR 420=2L+2L-8 OR 420=4L-8 OR 428=4L OR L=428/4 OR L=107 & WIDTH IS 107-4=103 

PROOF 2*107+2*103=420 OR 214+206=420 OR 420=420