Final answer:
The value of y is 12 in a parallelogram ABCD that is a rectangle.
Step-by-step explanation:
The given parallelogram ABCD is a rectangle. In a rectangle, opposite sides are equal. Therefore, AC = BD. We can set up an equation using the given information:
AC = 7y-13
BD = 3y+35
Setting the two expressions equal to each other:
7y-13 = 3y+35
Next, we solve for y by isolating the variable:
7y - 3y = 35 + 13
4y = 48
y = 12
Therefore, the value of y is 12.