A rational number is a number that can be written into a fraction. pi, some square roots, e, etc., are irrational numbers(numbers that cannot be written into a fraction).
The answer is 2x^2 to the question
AEB = CED = 180 - 45 - 14 = 121 deg
EDC = 180 - 121 - 27 = 32 deg
So angle D is 32 degrees
