So to solve, make an equation (x being the shorter side) 2x+2(7+x)=42 So just solve from here. 2x + 14 + 2x =42 4x=28 x=7 So the shorter side is 7, and the longer side is 14.
To find perimeter, we use this equation. 2L+2W=42 Let's say the longer side is the length. L=W+7 Let's plug that in for L. 2(w+7)+2w=42 2w+14+2w=42 Add like terms. 4w+14=42 Subtract 14 from both sides. 4w=28 Divide. 28÷4=7=W The shorter side is 7, which means the longer side is 14 cm.
