To find the value of X, simply know that for this parallelogram, the angles on each end that are diagonal with respect to each other are the same. And knowing that the angles in a parallelogram add up to equal 360 degrees. Simply make an algebraic expression equal to the value of 360 and then solve for x.
X + X + (X - 26) + (X - 26) = 360 2X + X - 26 + X - 26 = 360 4X - 52 = 360 4x = 412 X = 103.
The value for X, I believe would be 103 degrees. You can verify this by plugging in the value into both expressions, X and X-26 and see that if adding all the expressions together does it equal 360 degrees.
