Random numbers: which should i be using?

hi all,

ok here is the pieve of info i have been given from my challenge:

Use random numbers to simulate dart throwing. Get two random numbers for x and y coordinates. If (x - 0.5)² + (y - 0.5)² < .25, then the dart landed inside the circle.

ok then so when i use

r.Next();

everything is being missed and then when i use

r.NextDouble();

everything is being hit

surely i am missing something ?

i am then supposed to get the ratio of how many hit the circle to how many were thrown and then times it by 4 to give me an estimate of pi. i have that part sorted out its just this section where the random number is either always hitting or always missing

thanks