Answer:
a = 54 deg
Explanation:
Recall that for a triangle, any exterior angle equals the sum of its two remote interior angles (see attached for reference).
In our case the exterior angle is 2a and the remote interior angles are (a+10) and 44
hence,
2a = (a+10) + 44
2a = a + 10 + 44
2a = a + 54 (subtract a from both sides)
2a - a = 54
a = 54 deg