You ll also see a theme with one point in it, representing an observation point. This is a photograph taken from the observation point. Each raster cell is 30 m by 30 m., or 900 sq. An area of equal elevation.
Elevation is measured in meters also.
So you re ready to calculate the Viewshed, and we could tell you how to do this. Use the help menu to try to find out how to perform a viewshed analysis. Use what you learn from the help system to create a viewshed of all the parts of the area that would be visible from the observation point. 63,218 cells, at 900 sq.m. Take another look at the photograph in the View2 window.