Chapter 1
Number and Quantity
Course: Core Academic Skills For Educators Combined Test 5752
Subject: Core Academic Skills Educators Mathematics 5733
Chapter: Geometry
A circle is a two-dimensional figure defined as the set of all points that are the same distance from a fixed point called the center. The constant distance from the center to the edge is known as the radius, and twice the radius is the diameter. Understanding how to calculate the circumference and the area of a circle is important because these formulas are used in many real-life situations, from engineering and design to everyday tasks.
Circumference of a circle
The circumference of a circle represents the total distance around its edge. It can be calculated in two ways depending on whether the radius or the diameter is given:
- C=2πr where rrr is the radius.
- C=πd where ddd is the diameter.
The constant π(pi) is the ratio of the circumference of a circle to its diameter, and its approximate value is 3.14159.