I do not know if the angles of the directions I have to measure from the horizontal (x axis) or from the vertical (Y axis) in certain cases.
For example:
I say that an object is moving 90 km to the west, then changes course and moves 30 km to 50 ° southwest. Where do you measure this angle?
If I draw the Cartesian plane in the point that starts the second vector, which is my reference axis to measure it?
How do I do when I say northwest, southeast, or anywhere else? Will it always be my reference horizontal line? Are there rules?
For example:
I say that an object is moving 90 km to the west, then changes course and moves 30 km to 50 ° southwest. Where do you measure this angle?
If I draw the Cartesian plane in the point that starts the second vector, which is my reference axis to measure it?
How do I do when I say northwest, southeast, or anywhere else? Will it always be my reference horizontal line? Are there rules?
-
0 degrees is always the x-axis unless it says differently, and it rotates counterclockwise unless it says differently. But if you know the points on a compass you should know where it's pointing to. Southwest is in the third quadrant.
-
Look at 50° south west as 50° SOUTH of west, so go 50° down from negative side of x-axis.
Something like N50° W reads North, then 50° West. Meanwhile N 50° of West reads as West, then 50° North.
Something like N50° W reads North, then 50° West. Meanwhile N 50° of West reads as West, then 50° North.