Following program shows you how to calculate circle area.
In this tutorial will get circle radius from user and calculate area and prints it using following formula
Area = PI X r X r
var circleRadius = parseInt(prompt("Please enter the radius of circle:")); var areaOfCircle = Math.PI * (circleRadius * circleRadius); console.log("Area of circle is: " + areaOfCircle);
Please enter the radius of circle: 4 Area of circle is: 50.26548245743669