### Angles

## What are angles?

Angles are useful measurements and are often measured with protractors. There are 360⁰ degrees in a circle. An angle is formed when two lines (or sometimes rays) that are straight are intersecting with each other, where the number of degrees the vertex spans can be measured. The 3 types of angles that are everywhere in our lives are obtuse, acute, and right.

## Right Angles

The first type of angles is a “right angle,” which are angles that are **exactly 90⁰.** For example, all four angles in a square are 90⁰, so every square contains 4 right angles – a characteristic trait.

When pictures are being drawn with right angles, the artist will commonly draw another upside-down L-shape that forms a mini square with the right angle to demonstrate that they are trying to portray an** angle that is exactly 90 degrees**, even if it may not be exactly to scale. *(It is the same the other way around, if there is not a mini square drawn around an angle, it would not be best to assume it is a right angle!)*

## Obtuse Angles

A second type of angle is the obtuse angle. These are angles that are **wider than right angles, as they span more than 90 degrees.** Consider that triangles have a total of 180 degrees in all three of their angles combined. That means that there can only be one obtuse angle per triangle, if any; if there are two, it would already sum up to 180 degrees leaving none for the third angle!

## Acute Angles

Lastly, acute angles are the opposite of obtuse angles – you guessed it – **they are angles that classify as being less than 90 degrees**. A commonly used saying to help students remember that acute angles are the tiniest of all is that they are “a-CUTE” angles and therefore are small and cute!