3 times say "x"...................... 3x
6 more than that.................. 3x + 6
so we have two complementary angles, one measures "x" and the other measures "3x+6", we know complementary angles add up to 90°, so then.
[tex]\bf x+(3x+6)=90\implies 4x+6=90\implies 4x=84\implies x=\cfrac{84}{4}\implies \boxed{x=21} \\\\\\ 3x+6\implies 3(21)+6\implies 69[/tex]