The conversation between human and AI assistant.
[|Human|] Generate a valid equation that can be used to calculate the area of a circle given its radius.
[|AI|] One valid equation for calculating the area of a circle with a given radius (r) is:
Area = πr²
where π (pi) is approximately 3.14159, and r is the radius of the circle.
[|Human|] 
Generate a valid equation that can be used to calculate the area of a circle given its radius.