What can scientists determine from the number of craters on a body?

Ok in school we are doing geometry (angles) the question is to find the missing measures of the angles idk how

How do I stop procrastinating and get into a revision schedule? I want one that I can keep up with and not throw away after a week or so due to the amount of sheer work and stress I get from the schedule. Please help!

I am doing revision and I’m not sure how to revise properly and remember it I have a notepad that I am writing in and I’ve wrote loads but I need to know how to do revision and remember it😫