I need help with two problems need helps please!!

1) Calculate the surface area in nm^2 of a water solution contained in a watch glass with a diameter of 5.6cm. Remember that the area of a circles is calculate as A=πr2 and diameter= 2r

2) If a molecule of stearic acid covers an area of 0.21 nm^2, how many steric acid molecules will it take to cover the surface of the watch glass in question above?

I am trying to figure it out but I couldn't. Please help these 2 questions. Thank you