<script>
var geom = kendo.geometry;
var arc = new geom.Arc([75, 85], {
    radiusX: 25,
    radiusY: 15,
    startAngle: 45,
    endAngle: 135
});
var center = arc.getCenter();
console.log(center.x); // 75
console.log(center.y); // 85
</script>