Circumference: The circumference of a circle is the distance around its outer edge. It can be calculated using π multiplied by twice its radius (C = 2πr) or using π multiplied by its diameter (C = πd).
Area: The area of a circle is the amount of space enclosed by its boundary. It can be calculated using π multiplied by the square of its radius (A = πr^2).
Trigonometry: Trigonometry is a branch of mathematics that deals with the relationships between angles and sides in triangles. It heavily relies on ratios involving π, such as sine, cosine, and tangent.