In school, it can be difficult to see the real-life applications of geometry. Many people learn about shapes and lines, angles and planes without seeing their use and prevalence in everyday life. For many, geometry concepts remain abstract; however, if you look around, your eyes will quickly be opened to the role geometry plays in our world.
Every day all around you the abstract concepts you once learned in a classroom take life. Buildings and maps, photographs and drawings, and many more common objects paint a real-life picture of geometry applications. Just about any object, you can think of will use some form of geometry. Specifically, in a society run on selfies angles are an everyday occurrence. Here is a refresher of what angles are and how they are used in geometry.
Angles: A Closer Look
You might vaguely remember using a protractor at some point in your early education but may not remember exactly what determines the definition of an angle. The word angle is derived from the Latin word “angulus” which translates to “corner. ” In geometry, an angle is formed when two rays in a plane share an endpoint. In more basic terms, an angle forms at the corner of two lines; this intersecting point or endpoint is referred to as the vertex of an angle.
The Anatomy of an Angle
Angles have three main components: the vertex, two arms, and the degrees of the angle.
- The vertex. The vertex is the point where two rays meet to form a corner.
- The arms. The arms are another word for the two straight lines or rays that make up an angle.
- Angles are measured in degrees or the amount of turn between each arm that makes up the angle.
How to Label Angles
Angles are normally labeled using one of two methods.
- Give the angle a name. You can choose to label an angle giving it a name, which is usually a lower case letter of the Greek alphabet, such as α(alpha) or β (beta).
- Define an angle by the three letters (the two arms and vertex). Any shape uses a letter to label sides; an alternative way to label angles includes stating the letters of the two arms with the letter of the vertex in the middle.
Measuring Angles
Angles are most commonly measured in degrees; however, they can also be measured in radians. Degrees are a circular based measurement. There are 360 degrees in one full rotation of a circle; therefore, angle measurements can range from as little as 0 degrees to a full rotation of 360 degrees. Angles are normally measured using a tool called a protractor.
Types of Angles
Within geometry, there are many different kinds of angles some of which include:
- Corresponding angles. Corresponding angles are angles that are formed when a transversal line crosses two parallel lines. The angles that occupy the relative position at each intersection are denoted as corresponding angles.
- Obtuse Angle. An Obtuse angle is greater than 90 degrees but less than 180.
- Acute Angle. An Acute angle is less than 90 degrees.
Understanding the geometry of angles provides a useful tool for interpreting the world around you.