Are math problems getting you down? Well this should be of some help. Here is how to find a missing angle inside of a triangle. Now the first thing to remember when solving this type of question is that the sum of all the three angles inside a triangle is equal to 180 degrees. Therefore, whenever we have two of the three angles inside the triangle, all we have to do in order to obtain the missing angle is to add up the two known angles and subtract the total from 180 and we will get the missing angle.