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 that is measured in degrees.
The word comes from the Latin angŭlus, and is in turn from the Greek ἀγκύλος, which means “hunched over”.
In everyday use, the word angle can also be used as a synonym for corner (in the sense of the incoming angle), for example: “At what angle of the room do you prefer to put the sofa?”; corner or edge: “Beware of the angles of the table: you can hit yourself”; as well as from the point of view: “Have you already assessed the situation from all angles?”
Types of angles
According to its opening in degrees
| Null angle | It is that formed by two lines that coincide at its vertex and at its 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 semi-lines 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 that constituted by two semi-lines with a 180 ° vertex opening. |
| Oblique angle | Also called reflex or concave, it is one that has a top opening 180 ° and less than 360 ° |
| Perigonal angle | Also called full angle, it is one that has a 360 ° opening. |
Sum of angles
| Complementary angles | It is one that, together with another, adds an opening of 90 °. It may be consecutive angles or not in space, but they will be complementary provided that the sum of the degrees of their angles is 90 °. |
| Supplementary angles | It is called one that, together with another, adds an opening of 180 °. |
According to your position
| Center angle | It is one whose vertex is in the center of a circle. |
| Inscribed angle | The one where the vertex is a point of the circumference, and where it is, in turn, is cut by the semi-straight lines that constitute it. It consists of two ropes of a circle that converge at a common point of the circle forming a vertex. |
| Interior angle | The one that is inside a polygon. It is also called the angle whose vertex is in the inner part of the circumference and which is formed by ropes at whose point of intersection a vertex is formed. |
| Exterior angle | The vertex is located at a point external to the circumference and its sides are semi-straight that are, in relation to it, in a secant, tangent or both positions. |
| Seminscribed Angle | It is the one whose vertex is in the circumference, and is constituted of a rope and a tangent line that converge in the vertex. |
