Answer:
x = 3
y = 5
a = 14
z = 8
AC = ED = 15
BE = FA = 35
CF = DB = 21



Explanation:
First, we have to recognize that dimension of congruent shapes are equal. We are given the congruency statements:
From these statements, we can equate certain side lengths:
We can also identify through the Isosceles Triangle Theorem that:
because
and
have congruent base angles and are therefore isosceles triangles.
Hence, we can also declare that:
by the transitive property of equality.
Next, we can plug in the labeled values for these side lengths and solve for the variables:

⇒



____________

⇒


____________

⇒

Next, we can solve for z using the fact that CPCTC (Corresponding Parts of Corresponding Triangles are Congruent):


Finally, we can solve for the isosceles triangles' angle measures using our knowledge that the interior angles of a triangle add to 180°F.
(I will call the isosceles triangles' base angles
)

⇒

And we can solve for the rest of the angles using CPCTC:

Thus,


Further Note
When solving for the angle measures using the Law of Sines, we can see that the given side lengths do not match the angles. For example:



