# Angle

Computes the angle between two objects. If `geometry_status=2`, then `angle=angle2d`; if `geometry_status=3`, then `angle=angle3d`.

## Syntax

```angle2d(Conic)
```
```angle2d(Line)
```
```angle2d(Line, Line)
```
```angle3d(Plane, Line)
```
```angle3d(Plane, Plane)
```
```angle3d(Plane, Segment)
```
```angle(Point, Point, Point)
```
```angle(Polygon, Integer)
```
```angle(Triangle, Integer)
```

## Description

Computes the angle between a conic and the line $\left\{y=0\right\}$. For instance, if the conic is an ellipse, the angle computed is the angle formed by the line passing through the focus and the horizontal axis. If the conic is a parabola, the axis of symmetry is considered.

Computes the angle between a line and the horizontal axis.

Computes the angle between two lines.

Computes the angle between a plane and a line.

Computes the angle between two planes.

Computes the angle between a plane and the line defined by a segment.

Given three points $A$, $B$ and $C$, computes the angle between the lines created joining the points $A$ and $B$, and $B$ and $C$.

Given a polygonal or polygon and an integer $i$, computes the angle of the $i$-th vertex.

Given a triangle and an integer $i$, computes the angle of the $i$-th vertex.