Answer:
24 degrees.
Step-by-step explanation:
Let's let the two angles be A and B.
First, since they're complementary, they total 90. Thus:

If one angle (let's use A) is 18 more than twice the other, this means that:

Substitute this into the first equation:

Combine like terms:

Subtract 18 from both sides:

Divide both sides by 3:

So, angle B is 24 degrees.
And angle A is 2(24)+18=66 degrees.
So, the smaller angle is 24 degrees.
And we're done!