Final answer:
To prove that quadrilateral ABCD is a parallelogram, we need to show that opposite sides are parallel and congruent. In this case, we can use the properties of the diagonals. By setting up the ratio EC/BD = AE/BE and substituting the given values, we find that X = 4 and y = 12.
Step-by-step explanation:
To prove that quadrilateral ABCD is a parallelogram, we need to show that opposite sides are parallel and congruent. In this case, we can use the properties of the diagonals.
Since EC = 4 and BD = 12, we can set up the following ratio: EC/BD = AE/BE
Substituting the given values, we have 4/12 = x/y
Simplifying this ratio, we get 1/3 = x/y
Therefore, the values of x and y that prove that the quadrilateral is a parallelogram are x = 4 and y = 12. So, the answer is X = 4; y = 12.