First we have to know that the total size a outer angle with its inner angle equals to 180. Outer angle 1 = 92 180 - 92 = 88 = Inner angle 1 Outer angle 2 = 123 180 - 123 = 57 = Inner angle 2 And as long as we know two of the inner angles we can use the to solve for them third one. So,88 + 57 = 145 = 180 - 145 = 35 The angle no.3 = 35 Angle no.4 = 180 - 35 = 145 NOTE: I answered the first problem in another question. HOPE THAT HELPS.
