what does bearing/s of line/s mean in trigonometry?

The "bearing" means the direction of the line, relative to some fixed direction. Typically bearings are given in one of two ways:

1. As a "true bearing," measured in degrees clockwise from north. For example, a true bearing of 90 degrees means heading due east, and a true bearing of 350 degrees means 10 degrees to the left of north.

2. As a "relative bearing" measured in degrees from to the nearest north or south line. For example, "10 degrees west of north" is equivalent to a true bearing of 350 degrees, and 30 degrees east of south" is equivalent to a true bearing of 150 degrees.

If you'd like more info, check out this web site: Bearings (http://www.mathsteacher.com.au/year7/ch08_angles/07_bear/bearing.htm)