const lines = 5;
            let result = '';
            for (let i = 0; i ≤ lines; i++) {
                for (let k = 0; k < lines - i; k++){
                    result += ' ';
                }
                for (let l = 0; l < 2 * i + 1; l++ ) {
                    result += '*';
                }
                result += '\n';
            }
            console.log(result)