1 Answer

Circle Definition:
A circle is the set of all points in a plane at a fixed distance, called the radius, from a given point, the center.

Circle Formula:
Area of Circle = πr²
Diameter of Circle = 2r
Circumference of Circle = 2πr = πd
Area of Sector = πr²(θ/360)
where
r = radius
Circle Image/Diagram

Circle Example:
Case 1: Find the area, diameter and circumference of a circle with the given radius 3.

Step 1: Find the area.
Area = πr² = 3.14 * 3² = 3.14 * 9 = 28.26.

Step 2: Find the diameter.
Diameter = 2r = 2 * 3 = 6.

Step 3: Find the circumference.
Circumference = πd = 3.14 * 6 = 18.84.

Case 2: Find the area of sector with the given radius 3 and theta 30.

Step 1: Find the area.
Area =πr²(θ/360) = 3.14 * 3² * (30/360) = 3.14 * 9 * 0.083 = 2.35.

The above example will clearly illustrates how to calculate the Area, Diameter and Circumference of a Circle, Area of Sector manually.