Question 947517
L=Length=2W; W=Width
Area=A=L*W  Substitute for L
A=2W*W 
{{{128 sq cm=2W^2}}} Divide each side by 2
{{{64 sq cm=W^2}}}  Find the square root of each side
8 cm=W ANSWER 1: The width is 8 cm.
L=2W=2(8 cm)=16 cm ANSWER 2: The length is 16 cm.
CHECK
Area is 128 sq cm
A=L*W
128 sq cm=16 cm x 8 cm
128 sq cm=128 sq cm