The Lesson
The angular coordinate is the second number in the pair of numbers used to describe
polar coordinates.
For example, in the polar coordinates
(5, 45°), angular coordinate is
45° (the number on the right):
The angular coordinate is sometimes called the polar angle or the azimuth.
It can be measured in
degrees or
radians.
What Does the Angular Coordinate Mean?
The angular coordinate tells you what
angle the point is (in the counter-clockwise direction) from the polar axis.
If a point has polar coordinates
(5, 45°), the point would be
45° from the polar axis. The image below shows what we mean by a point being 45° from the polar axis:
Using a Polar Grid to Find the Angular Coordinate
A polar grid can be used to find the angular coordinate.
A polar grid is shown below:
A line from the pole is shown in
red. If we read along the line, we see that it is labelled
45°. All points on this line are
45° from the polar axis.
Counter-Clockwise
The angular coordinate is measured in the
counter-clockwise (or
anti-clockwise) direction:
Make sure you do not measure the angular coordinate in the clockwise direction: