1) L = Length, W = Width, perimeter = 36
then
2L+2W =36
L = 2W
of the equation 1 , find W
2L+2W = 36⇒2L=36-2W⇒L= 36-2W/2⇒L= 18-W
Now substitute it value with the equation 2
18-W = 2W⇒18 =2W+W⇒18= 3W⇒W= 18/3 = 6, L = 18-6 = 12
NOW SUBSTITUTE THE VALUES IN THE EQUATION 1
2* 12+ 2*6 = 36 , IT IS FULFILLED