محاسبه مساحت

ابتدا اين كد را در قسمت head كپي كنيد

<SCRIPT LANGUAGE="JavaScript">

function doArea(num) {
switch(num) {
case 0 : return (""); break;
case 1 : var length = prompt("Please enter the length of your square:", "");
length = length * length;
return (length); break;
case 2 : var width = prompt("Please enter the width of the base:", "");
var height = prompt("Please enter the height of the triangle:", "");
return (width * height / 2); break;
case 3 : var width = prompt("Please enter the width of your rectangle:", "");
var height = prompt("Please enter the height of your rectangle:", "");
return (width * height); break;
case 4 : var radius = prompt("Please enter the radius of the circle: ", "");
return (Math.PI * Math.pow(radius, 2)); break;
case 5 : var radius = prompt("Please enter the radious of the sphere:", 0);
return (4 * Math.PI * (Math.pow(radius, 2))); break;
}
}

</script>

و كدهاي زير را در قسمت body كپي كنيد

<center>
<form name=calcarea>
Find the area of a
<select name="shape" size="1" onChange="this.form.area.value = doArea(this.selectedIndex);">
<option> ...
<option value="square">Square
<option value="triangle">Triangle
<option value="rectangle">Rectangle
<option value="circle">Circle
<option value="sphere">Sphere
</select>
= <input type=text name=area size=10>
</form>
</center>