If cos(a)=0.95 and sin(b)=0.95, what can be said about angle a and angle b?

Aproduction process manufactures electronic components with timing signals whose duration follows a normal distribution. a random sample of 10 components was taken, and the durations of their timing signals were measured. a. the probability is 0.05 that the sample variance is bigger than what percentage of the population variance? b. the probability is 0.10 that the sample variance is less than what percentage of the population variance?