Let
x = length of one side
y = another length
The second statement is expressed algebraically into
x = 2y - 3
The formula for a perimeter P of a kite (as a parallelogram shaped):
P = 2x + 2y
Since x = 2y - 3 and P = 66, substitute them into
66 = 2(2y - 3) + 2y
Solving for y,
66 = 4y - 6 + 2y
66 = 6y - 6
-6y = -6 - 66
-6y = -72
(-6y)/-6 = -72/-6
y = 12
Solving for x using the expression,
x = 2y - 3
x = 2(12) - 3
x = 24 - 3
x = 21
Therefore the length of the two sides are 12 and 21.