4.9.1 Top new questions this week

4.9.1.1 \pi day riddles for LaTeX users
4.9.1.2 Getting ducks in example images
4.9.1.3 About the use of curly braces
4.9.1.4 TikZ: How to draw a pattern at the border of a tikz path
4.9.1.5 How to declare a "bracket-style" math operator
4.9.1.6 Shortening and decorating a path
4.9.1.7 equation alignment in a two-column table
4.9.1.1 \pi day riddles for LaTeX users

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=420083

This is a maybe not too serious question, but in order to honor \pi day  I'd like to collect a set of LaTeX riddles. The aim is to encourage newcomers to learn some very basic LaTeX commands. Here is  ... 
[fun]
 
asked by marmot https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=121799 22 votes
answered by egreg https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=4427 14 votes
4.9.1.2 Getting ducks in example images

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=419751

This question led to a new package: 
duckuments 
There are lots of cool example pictures in LaTeX. As far as I'm aware there aren't any good example duck images ;-( 
Having ducks in the example  ... 
[graphics] [fun] [examples] [tikzducks]
 
asked by ThorbjA~,rn E. K. Christensen https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=125223 22 votes
answered by Ulrike Fischer https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=2388 19 votes
4.9.1.3 About the use of curly braces

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=420197

Although I use LaTeX a lot, I still have a lot to learn about it, and I still have many questions which remain unanswered. One in particular bothers me: when and why must I use curly brackets when  ... 
[math-mode] [math-operators] [syntax]
 
asked by Samuel Diebolt https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=74462 13 votes
answered by barbara beeton https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=579 15 votes
4.9.1.4 TikZ: How to draw a pattern at the border of a tikz path

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=419533

I want to draw the shapes of airspaces according to the german VFR map style and I have problems with the restricted areas, ED-R44 in this picture: 
I already found out how to do the airspace A and  ... 
[tikz-pgf] [pattern]
 
asked by TobiBS https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=156791 11 votes
answered by marmot https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=121799 6 votes
4.9.1.5 How to declare a "bracket-style" math operator

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=419860

This has most likely been asked before, but I wasn't able to articulate the question in a way that yielded relevant search results. 
How do you declare a math operator to simplify an expression such  ... 
[math-mode]
 
asked by tmakino https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=149335 10 votes
answered by Mico https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=5001 14 votes
4.9.1.6 Shortening and decorating a path

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=419482

Placing an arrow as decoration on a path which has been shortened leads to a misplacement of the arrow. This is potentially emphasized if the looseness key has been used. In this other question (and  ... 
[tikz-pgf] [pgf-decorations]
                                                                                  

                                                                                  
 
asked by Axel Krypton https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=128737 7 votes
answered by marmot https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=121799 2 votes
4.9.1.7 equation alignment in a two-column table

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=420230

I am having trouble making a table of equations line up properly. 
I would like to align the '=' sign for the Division row, but when I do I end up with something like this: 
Here is the code I  ... 
[tables] [horizontal-alignment] [equations] [arrays]
 
asked by UNRMath https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=157188 6 votes
answered by egreg https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=4427 5 votes