Answer:
,the value of y is 27 degrees.
Explanation:
Since the opposite angles of a parallelogram are equal, we know that angle x is also 51 degrees.
Now, we can use the fact that the sum of angles in a triangle is 180 degrees to find the missing angle, which we can label as z.
x + y + z = 180
51 + y + z = 180
y + z = 129
We can also see that angle z and angle 78 form a straight line, so they add up to 180 degrees.
z + 78 = 180
z = 102
Now we can solve for y:
y + z = 129
y + 102 = 129
y = 27