Maria cut a pizza into 8 equal pieces she put each slice on 3 plates what is the measure of the angle for the slices that are left

A circle has a total number of 360 degrees, so you would divide 360 by 8, and that would tell you how many degrees each slice is:
360 / 8 = 40
 After that, you would subtract 3 from 8 to show that there are 5 pieces left:
8 - 3 = 5
which you would then multiply by 40 because each slice is 40 degrees, so you would get an answer of
5 x 40 = 200 degrees.