It is given that the circumference of the circle is 19.5 inches. Let the diameter is d inches .
And the formula of circumference is

Substituting the value of C, we will get

When the diameter increased by 3, then the circumference is

And the circumference , when diameter is increased by 3 is 29 inches .
the sum of 12 and a number/n
Complementary angles are angles whose sum is 90 degrees.
90 - 67 = 23
23 degrees is the measure of its complementary angle.