Question 341238
If two angles are complementary, they add to 90.

Thus the angles are x and 90-x (that's tricky, reason it out why it is so)...
Then
(90-x) = 21 + 2x
90 - x = 21 + 2x
Now subtract 21 and add x to both sides in two steps...
69 = 3x
x = 23
90-x = 67