What is the definition for angle addition postulate for the measure of an angle? This is from a geometry pre-test vocabulary worksheet. I am in 9th...

The angle addition postulate states that if a point is
within an angle and you add the two angles that are made by drawing a line through the
point that the total will equal the large angle.  For example, point D lies in the
middle of angle ABC, the angles ABD and CDB will add up to angle
ABC.

An angle can be measured in degrees or radians. The
definition for meausre of an angle accoriding to href="http://mathopenref.com">http://mathopenref.com
is 

Measure of an angle

In
geometry an angle is measured in degrees, where a full circle is 360 degrees. As in the
figure above, a smallish angle might be around 30 degrees. For very small angles, the
degree is further divided in to 60 minutes. For even smaller measurements the minute is
divided again into 60 seconds, However this last measure is so small, it only used where
angles are href="http://www.mathopenref.com/subtend.html">subtended over extreme
distances such as astronomical measurements, and measuring latitude and
longitude.

Measure of an
angle

In geometry an angle is measured in degrees, where a
full circle is 360 degrees. As in the figure above, a smallish angle might be around 30
degrees. For very small angles, the degree is further divided in to 60 minutes. For even
smaller measurements the minute is divided again into 60 seconds, However this last
measure is so small, it only used where angles are href="http://www.mathopenref.com/subtend.html">subtended over extreme
distances such as astronomical measurements, and measuring latitude and
longitude.