The prallelogram whose adjacent sides are equal and one vertex angle is 90 degrees is a square.
The value of angle 1 is 90 degrees as the diagonal of the square intersect at 90 degrees.
The value of y is 23.
The diagonal of the square bisect the vertex angle hence the angle of 3x is 45 degrees.
Thus, the value of x is 15 degrees.
The value of 12z is 45 degrees.
Thus, the required value of z is 3.75 degrees.
