## What is Angle:

Angle is a concept of Geometry to refer to the **space between the intersection of two lines that start from the same point or vertex**and which is measured in degrees.

The word comes from the Latin *angleus*and this in turn from the Greek ἀγκύλος, which means “bent”.

In everyday use, the word angle can also be used as a synonym for corner (in the sense of an incoming angle), such as: “At what angle of the room do you prefer to put the sofa?”; corner or edge: “Be careful with the angles of the table: you can hit yourself”; as well as point of view: “Have you evaluated the situation from all angles yet?”

## types of angles

### According to its opening in degrees

null angle | It is the one formed by two lines that coincide at their vertex and at their ends, therefore, its opening is 0°. |

Acute angle | It is one with a vertex opening greater than 0° and less than 90°. |

Right angle | It is made up of two rays whose vertex opening is 90°. |

Obtuse angle | It is one whose vertex opening is greater than 90° and less than 180°. |

flat angle | It is the one made up of two rays with a vertex of 180° opening. |

oblique angle | Also called reflex or concave, it is one that has a vertex opening above 180° and less than 360° |

perigonal angle | Also called a complete angle, it is one that has an opening of 360 °. |

#### sum of angles

complementary angles | It is the one that, together with another, adds an opening of 90 °. They may or may not be consecutive angles in space, but they will be complementary as long as the sum of the degrees of their angles is 90°. |

supplementary angles | It is called the one that, together with another, adds an opening of 180 °. |

### According to your position

center angle | It is the one whose vertex is in the center of a circumference. |

inscribed angle | The one where the vertex is a point of the circumference, and where this, in turn, is cut by the rays that constitute it. It is made up of two chords of a circle that meet at a common point of the circle forming a vertex. |

inside angle | One that is inside a polygon. It is also called the angle whose vertex is on the inside of the circumference and which is formed by chords at whose point of intersection a vertex is formed. |

outside angle | The vertex is located at a point external to the circumference and its sides are rays that are, in relation to it, in a secant position, tangent or both. |

semi-inscribed angle | It is the one whose vertex is on the circumference, and is made up of a chord and a tangent line that converge at the vertex. |

See also Type of angles.