# Geometry Party: Accuracy Angle Hour

If you’ve ever tried to shoot a bow and arrow you know that angle is everything when you’re trying to hit your target. So to celebrate Accuracy Happy Hour in a geometric way, let’s get angular and learn more about what happens when two lines meet!

In Euclidean geometry, all angles have the same structure – two rays that meet at an endpoint, called the vertex. The angle is defined as the space between these intersecting lines. The angle symbol looks like: ∠

The word “angle” has its origins in the Proto-Indo-European root ank-, meaning “to bend” or “bow”. The english word “ankle” has the same root, which makes sense considering all the angles you can create between your foot and leg when you bend your ankle!

Angles are measured in degrees, and can range from between 0 and 360 degrees. Besides measuring angles in degrees, we also have names for special categories of angles! Let’s explore them!

- One of the most popular angles is the
**right angle**! These angles occur when two perpendicular lines meet, and always measure 90°. In geometry the image of a right angle has a special symbol – a box – to indicate that the angle is right. Other types of angles use a curve to indicate the angle being referred to. - There are special names for other angles that measure in multiples of 90°. A 180° angle is called a
**straight angle**, and is where the position of the rays create a straight line. An angle that goes the full 360° is called a**full angle, round angle,**or**perigon**. - Any angle that doesn’t measure in multiples of 90° is called an oblique angle. There are also specific names for angles that measure within certain degree ranges. They are the
**acute angle**(inside 0° and 90°), the**obtuse angle**(inside 90° and 180°) and the**reflex angle**(inside 180° and 360°). - An angle that never gets going (0°) is called, fittingly, a
**zero angle**.

Angles also sometimes like to hang out together, and geometry has lots to say about these friendly angle pairs!

- Two angles that are equal in measurement are called
**congruent angles**. - When two lines intersect, the angles that mirror each other are called
**vertical angles**or**opposite angles**. They’re always equal to each other. **Adjacent angles**share a vertex and one arm.**Complimentary angle**s are pairs of angles that sum to 90°.**Supplementary angles**are pairs of angles that sum to 180°.**Explementary angles**or**conjugate angles**are pairs of angles that sum to 360°.

If you want to dive even deeper into the world of angles, you might try trigonometry, which specifically studies the relationships between the sides and angles of triangles. We won’t go too far down the trig rabbit hole, but it’s a powerful branch of mathematics that has been studied since the 5th century and has applications in astronomy, navigation, optics, acoustics, engineering, number theory, and many more!

Angles are pretty simple, but also extremely useful, with many mathematical applications. So angle yourself towards Accuracy Happy Hour, and get ready for an acutely geometric good time!

Full schedule:

Session 1 – **8:00 AM to 10:00 AM on 8/19**

Session 2 – **2:00 PM to 4:00 PM on 8/20**

Session 3 – **10:00 PM to midnight on 8/20**

HQ will bestow typical Happy Hour bonuses for your work during each of those time frames, but there’s more than that to earn! Check your in-game notifications to see the full accuracy bonus breakdown.

**Swag (made possible by generous donations from Eyewirer @susi):** Most accurate player completing at least 30 cubes wins their choice of face mask, notebook or mug, plus a magnet! Second and third place will each also win a magnet.

**Mentors:** You are still allowed to mentor people during these time windows. Please just use your best judgment as to whether someone is asking you for basic newbie help vs. trying to have you boost their accuracy on cube after cube.

**Scythes:** Please avoid scything during these time windows. Even though accuracy for this will be retroactively calculated, we would prefer to go with accuracy based on players’ raw tracing. By the time this challenge is scored, don’t worry, admins will have corrected consensus as needed.

*Artwork by Daniela Gamba*