function start(){
    var operation = readLine("What operation do you want to use? ");
    if(operation == "circumference"){
        var radius = readLine("What is the radius? ");
        var circumference = (radius * radius) * 3.14;
        println("The circumference is " + circumference);

    }else if(operation == "squareroot"){
        var number = readLine("Choose a number to square root. ");
        var sqrt = Math.sqrt(number);
        println("The square root of " + number + " is " + sqrt);

    }else if(operation == "hypotenuse"){
        var leg1 = readInt("What is the first leg? ");
        var leg2 = readInt("What is the second leg? ");
        var hypotenuse = (leg1 * leg1) + leg2 * leg2;
        println("The hypotenuse is " + hypotenuse );
        }
}