Angles on a straight line add up to 180 degrees.
Through any three non-collinear points, exactly one plane can be defined. If the three points are collinear (lying on a single straight line), then an infinite number of planes can be created, as any plane containing that line will also pass through those points. Thus, the relationship between the points determines the number of planes possible.
Yes, 2 angles can have 3 points in common. Two angles of the same number of degrees can be superimposed on each other and would share all points. Or, you could choose 3 points on one line segment, while having two other line segments which do not share points, and which delineate different angles.
A straight line, through the origin, with a gradient of 1/2.
Origin
line segments
In plane geometry there is exactly one straight line through two points. There can be any number of curved lines.
1 straight line. An infinite number of curved lines.
You need two points to determine a line. A single point can have an infinite number of lines passing through it.
An ellipse is a conic section, a curving line which is the path of a point that moves in such a way that the sum of its distance from two fixed points is constant.... so no - there are not 4 straight angles in an ellipse, nor any straight bits at all.
Through any three non-collinear points, exactly one plane can be defined. If the three points are collinear (lying on a single straight line), then an infinite number of planes can be created, as any plane containing that line will also pass through those points. Thus, the relationship between the points determines the number of planes possible.
== == Through any two points there is exactly one straight line.
Yes, 2 angles can have 3 points in common. Two angles of the same number of degrees can be superimposed on each other and would share all points. Or, you could choose 3 points on one line segment, while having two other line segments which do not share points, and which delineate different angles.
It is the shortest distance between two points.
A straight line, through the origin, with a gradient of 1/2.
It is an collection of an infinite number of points.
Origin
line segments