How to find CDF on disk [duplicate]

Let $Z = (X, Y)$ be a random variable uniform inside circle of radius $R$. How to find cumulative distribution function (CDF) on disk?

• Self-duplicate of math.stackexchange.com/q/1931107 Please stop that. – Did Sep 27 '16 at 11:56
• I reopened because the question was closed and I modified completely,but don't reopened. – Wagner Jorge Sep 27 '16 at 16:21
• Yes, and this is called cheating the system, so: Please stop. – Did Sep 27 '16 at 18:40
• I don't had knowledge, sorry. Please delete the question. I don't have the intention of to use cheat of system. I repeat I don't had knowledge. You can delete this question. Thank you for your help. – Wagner Jorge Sep 27 '16 at 20:03

$$P(X<x,Y<y)=\frac{\text{red area(x,y)}}{R^2\pi}$$