Take a clue from the info that Angles A and B have the same measure. Then the sum of Angles A and B is 2A (we have eliminated B). Now this 2A plus the measure of Angle C add up to 180 degrees: 2A + (A+48).
Then 2A + A + 48 = 180, or 3A = 228, or A = 76 degrees.
Thus, 180 - 2(76) = 28.
The three angles are as follows: A = B = 76 degrees, and C is 28 degrees.
Check: Do A, B and C sum up to 180 degrees, as they must?
Does 76 + 76 + 28 (degrees) add up to 180 (degrees)? Yes.