It is given that two complementary angles are in the ratio 2:1.
Consider 2x and x as the angles.
We know that, if two angles are complementary, then their sum is 90o.
Then, 2x+x=900
⟹ 3x=900
⟹ x=903=30.
Here, the angles will be x=300 and 2x=2×30o=600.