I'm teaching myself calculus and I can't figure out how to do the problems below. Please explain how to do them because my book is confusing me.

Find the area of the region:

1.) Inside r = 2acos(theta) and outside r = a

Find the length of the curve over the given interval:

2.) r = 2acos(theta)

3.) r = 8(1+cos(theta))

Thank you!