<script>
var geom = kendo.geometry;
var center = [30, 30];
var options = {
    radiusX: 25,
    radiusY: 15,
    startAngle: 45,
    endAngle: 225,
    anticlockwise: true
};
var arc = new geom.Arc(center, options);
console.log(arc.startAngle); // 45
</script>