function arguments(input) {
    var figure = input.shift();
    if (figure == "square") {
        let a = Number(input.shift());
        let area = (a * a).toFixed(3);
        console.log(area);
    }
    else if (figure == "rectangle") {
        let a = Number(input.shift());
        let b = Number(input.shift());
        let area = (a * b).toFixed(3);
        console.log(area);
    }
    else if (figure == "circle") {
        let r = Number(input.shift());
        let area = (r * r * Math.PI).toFixed(3);
        console.log(area);
    }
    else (figure == "triangle") {
        let a = Number(input.shift());
        let h = Number(input.shift());
        let area = (a * h / 2).toFixed(3);
        console.log("area");
    }
}