Let x be the one angle.
So, the complement of x=90o−x.
Given, two complementary angles differ by 20o.
⇒x−(90o−x)=12o
⇒x−90o+x=12o
⇒ 2x=12o+90o
⇒ x=102o2
⇒ x=51o.
Therefore, complementary of x,
=90o−x
=90o−51o
=39o.
Hence, 51o and 39o are the complementary angles.