Answer:
120 degrees
Step-by-step explanation:
Let the constant of proportionality between the angles of the given triangle be x.
Hence,
The Measure of The First Angle = 2x
The Measure of The Second Angle = 3x
The Measure of The Third Angle = 10x
The Angle Sum Property Of A Triangle says that the sum of all angles of any triangle is 180.
Hence,

As the Constant Of Proportionality obtained is 12
Hence,
The Measure of The First Angle = 2*12 = 24
The Measure of The Second Angle = 3*12 = 36
The Measure of The Third Angle = 10*12 = 120
As The Third Angle is the largest, its measure is 120.