Geometric Distribution/Confidence Intervals

**A die is thrown repeatedly and independently until the score of 6 is obtained. This happens to be on the 8th throw. Find an equi-tailed 95% confidence interval for theta=P(six)?**

I understand that the die process follows a geometric distribution. But I can only understand confidence intervals when using a normal distribution? I can calculate the E(X) and Var (X) for the distribution, but i don't see how to calculate the confidence interval? As far as I'm aware the geometric distribution has no fixed "n" and therefore can't calculate the interval in the same way.

Regards