One angle of an isosceles triangle is 100 degrees. Which other angles could be in that isosceles triangle? 40,30,20,70

An isosceles triangle has two identical angles and one different angle. In this case our different angle is 100. We know that there is 180 degrees in a triangle. So you subtract 180-100= 80. We still have 2 identical angles to find. So since they are identical you can evenly distribute the 80 by dividing it by 2. Which is 40. The answer is 40