triangel....& maebee 2 sides the same leng . . . ######## BAD: "longer sides" me assume yu meen the 2 sides . . . that be the same leng. . . . assume 2...other side be the base . . . 1......rim-leng=25 . . .=sum av 3 sides . . . 2......leng av 1 side=2*base-3 . . . base+(2*base-3)+(2*base-3)=25 . . . 5*base -6=25 . . . 5*base=31 . . . base=31/5 =6.2. . . other side=2*6.2-3=12.4-3=9.4 . . . rim-leng=6.2+9.4+9.4=25