var viewer = new Cesium.Viewer('cesiumContainer');
var polygon = viewer.entities.add({
    name : 'Polygon',
    polygon : {
        hierarchy : Cesium.Cartesian3.fromDegreesArray([-115.0, 38.0,
                                                        -115.0, 32.0,
                                                        -105.0, 32.0,
                                                        -105.0, 37.0]),
        material : Cesium.Color.RED
    }
});


var label = viewer.entities.add({
    label: {
        text: polygon.name,
        verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
        horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
        eyeOffset: new Cesium.Cartesian3(0,0,-200)
    },
    position: Cesium.Cartesian3.fromDegrees(-110, 35)
});