You can measure these parameters from various 2D surfaces: Ellipse, Polygon, Rectangle, Pen.

The parameters of 2D surface will be displayed in the properties window of annotations and ROIs:

Some information about this region of interest will be displayed in the bottom right corner of the image. The information displayed by default depends on your settings in the preferences panel.

To modify pixel thresholds, see: How to optimize measures of areas, deviation standards on other statistics using pixel thresholds on 2D surfaces?

To accumulate the values of several 2D surfaces, see: How to accumulate the measure of areas, deviation standards and other statistics of separated surfaces?