ABCD is a rectangle. What is the value of x?

Explanation
We can use pythagorean theorem to solve for the value of x:
45^2 + x^2 = 53^2
2025 + x^2 = 2809
We now subtract 2025 from both sides:
2809 - 2025 = 784
x^2 = 784
Square both sides
[tex]\sqrt{784}[/tex] = 28
x = 28
Answer
The value of x is 28