# How to complete a noisy perspective rectangle?

I have an image of a rectangle that is noisy (perspective image).

I know the value of $$x$$, $$y$$, and angle $$3$$. Angles "$$2$$" and "$$4$$" are not accurate. Also, I know the real rectangle size. The angle "$$1$$" is noisy. I want to complete the rectangle and calculate the angle "$$4$$" in the image.

Having this information, can I calculate the angle "$$4$$" and complete the rectangle?

• When you say "rectangle", do you mean a quadrilateral? Otherwise, knowing x and y means you know everything. – Jens Feb 12 at 20:06
• Yes. I mean perspective rectangle – Mostafa Farzane Feb 12 at 20:14

Can I calculate the angel "4" and complete the rectangle?

My suggestion is to estimate the value of angle $$4$$ in the following steps:
4. Finally, estimate the angle $$4$$ by computing the angle between the two lines that interpolate the edges incident in angle $$4$$.