Find the Circumference and Area of Circles
All circles have exactly the same shape, but their sizes are affected by the length of the radius, a line segment from the center to any point on the circle. A line segment that passes through a circle's center connecting two points on the circle is called a diameter. The diameter is twice as long as the radius.
The size of a circle can be measured in two ways. The distance around a circle is called its circumference.
Dividing the circumference by the diameter always gives the same number. The value of this number is pi, symbolized by the Greek letter π. However, the exact value of π cannot be calculated since the decimal never ends or repeats. We usually approximate it by substituting 3.14 as the value and use the symbol ≈ to show that the result is appropriate, not exact.
