We know, two angles are said to be complementary, if the sum of their measures is 90∘.
Let the angle be x∘ and its complement is 90∘−x∘
Then, according to the statement,
⇒x∘=(90∘−x∘)−28∘
⇒x∘+x∘=90o−28∘
⇒2x∘=62∘
⇒x∘=62∘2=31∘.
Hence, the measure of the angle is x=31∘
and its complement is 90o−x=90o−31o=59∘.