How to find the area of a circle using js

Method to calculate the circle area: 1. Create an input tag and receive the radius value; 2. Use "document.getElementById('id').value" to get the radius value in the input input box; 3. , use the area formula "area=3.14*(radius*radius)" to find the area of the circle.

The operating environment of this tutorial: Windows 7 system, JavaScript version 1.8.5, Dell G3 computer.

The specific condition is to enter a radius, then find the area, round to 2 decimal places,

    
  输入圆的半径：    

[Recommended learning:javascript video tutorial]

The above is the detailed content of How to find the area of a circle using js. For more information, please follow other related articles on the PHP Chinese website!