👉 Goniometrically, a concept in mathematics, it refers to the relationship between two angles. It is named after the Greek mathematician and physicist Eratosthenes who discovered that when an object rotates, its angle of rotation is equal to the inverse cosine (cos-1) of the radius of rotation divided by the length of the arc. For example, if a circle has circumference 20 and radius 7 units, then the angle θ between the center of the circle and
