/line - линия; line segment - отсечка; ray - лъч; angle - ъгъл; /
When two rays share a point they form an angle.
Slope
A slope of a line is the change in
To find the slope of
If the slope of a line is zero, then the line is perfectly horizontal.
If the slope of a line is undefined, then the line is perfectly vertical.
If a line is perfectly vertical & another line is perfectly horizontal, then the lines are perpendicular to each other.
Parallel lines
If the slopes of two lines are equal, then they are parallel.
Perpendicular lines
If the slope of one line is the negative and reciprocal of the another line, then the two lines are perpendicular.
Distance
In two-dimension
The distance between two points in the second dimension can be found using:
In three-dimension
Midpoint
The midpoint of a line segment is the point that is equidistant from both endpoints of the line segment. It bisects the segment.
To find the midpoint of a line segment