Let us assume the angle be xo Then it’s complement angle is 4xo.
When the sum of two angles is 90°, then the angles are known as complementary angles. If two angles add up to form a right angle, then these angles are referred to as complementary angles.
4x + x = 90o
5x = 90o
x = 18o
∴ The angle x = 18o and
Its complement 4x = (4×18o) = 72o