  The areas of sunspots are the most prominent feature of the development of
sunspot groups. Since the size of sunspot areas depend on the strength of the
magnetic field, accurate measurements of these areas are important. In this
study, a method which allows to measure true areas of the sunspots is
introduced. A Stonyhurst disk is created by using a computer program and is
coincided with solar images. By doing this, an accurate heliographic coordinate
system is formed. Then, the true area of the whole sunspot group is calculated
in square degrees with the aid of the heliographic coordinates of each picture
element forming the image of the sunspot group. This technique's use is not
limited with sunspot areas only. The areas of the flare and filaments observed
on the chromospheric disk can also be calculated with the same method. In
addition to this, it is possible to calculate the area of any occurrence on the
solar disk, whether it is related to an activity or not.
