Circle Equation

The standard form of a circle equation is (x − h)² + (y − k)² = r², where (h, k) is the centre and r is the radius. This form makes it easy to identify the centre and radius directly.

1. 1Standard form: (x − h)² + (y − k)² = r²
2. 2Centre is at (h, k)
3. 3Radius r = √[(x−h)² + (y−k)²]
4. 4Area = πr², Circumference = 2πr