Answers.Body: <p>The part is <a href="https://rebrickable.com/parts/4190/plate-special-2-x-2-with-double-inverted-curve-1-stud/" rel="noreferrer">Plate Special 2 x 2 with Double Inverted Curve, 1 Stud (4190)</a>.</p>
  <p><a href="https://i.sstatic.net/CVXIY.png" rel="noreferrer"><img src="https://i.sstatic.net/CVXIY.png" alt="Part render" /></a></p>
  <p>It was introduced in a few sets in 2023. It's original use was to provide an upward curve on roofs. This can be seen very easily in <a href="https://rebrickable.com/sets/21060-1/himeji-castle/" rel="noreferrer">Himeji Castle (21060)</a>:</p>
  <p><a href="https://i.sstatic.net/0Iyvz.png" rel="noreferrer"><img src="https://i.sstatic.net/0Iyvz.png" alt="Himeji Castle" /></a></p>
  <p>It can of course be used for many other things. Trivially, these parts can be tiled to create small peaks in a 4x4 area:</p>
  <p><a href="https://i.sstatic.net/pckNX.png" rel="noreferrer"><img src="https://i.sstatic.net/pckNX.png" alt="4x peak" /></a></p>
  <p>These parts are also compatible with some of the other recent inverted curved slope elements. For example, here it is next to <a href="https://rebrickable.com/parts/73682/brick-curved-internal-double-3-x-3-with-13-inverted-cutout-corner/" rel="noreferrer">Brick Curved, Internal Double, 3 x 3 with 1/3 Inverted Cutout, Corner (73682)</a>:</p>
  <p><a href="https://i.sstatic.net/uPki5.png" rel="noreferrer"><img src="https://i.sstatic.net/uPki5.png" alt="Profile comparison 3x3 Curved Slope Double 73682" /></a></p>
  <p>This is the same profile as <a href="https://rebrickable.com/parts/70681/brick-curved-3-x-1-with-13-inverted-cutout/" rel="noreferrer">Brick Curved, 3 x 1 with 1/3 Inverted Cutout(70681)</a>:</p>
  <p><a href="https://i.sstatic.net/8ABEQ.png" rel="noreferrer"><img src="https://i.sstatic.net/8ABEQ.png" alt="Profile comparison 1x3 Arch Inverted 70681" /></a></p>
  <p>This curve also aligns perfectly with the curve of the <a href="https://rebrickable.com/parts/93273/slope-curved-4-x-1-double-with-no-studs/" rel="noreferrer">telephone bow</a>, assuming that is can be inverted:</p>
  <p><a href="https://i.sstatic.net/v1ZMy.png" rel="noreferrer"><img src="https://i.sstatic.net/v1ZMy.png" alt="93273 render" /></a></p>
  <p>Here's one way those parts can be used together:</p>
  <p><a href="https://i.sstatic.net/T388K.png" rel="noreferrer"><img src="https://i.sstatic.net/T388K.png" alt="Telephone bow compatibility" /></a></p>
  <p><a href="https://i.sstatic.net/a8zlq.png" rel="noreferrer"><img src="https://i.sstatic.net/a8zlq.png" alt="Telephone bow front" /></a></p>
  <p>Because the telephone lines up with a pair of these, the <a href="https://rebrickable.com/parts/11477/slope-curved-2-x-1-no-studs-12-bow/" rel="noreferrer">2x1 bow slope</a> also lines up easily:</p>
  <p><a href="https://i.sstatic.net/IGjSb.png" rel="noreferrer"><img src="https://i.sstatic.net/IGjSb.png" alt="11477 Render" /></a></p>
  <p>The notched variant (29119/29120) of those slopes are also compatible:</p>
  <p><a href="https://i.sstatic.net/FIa0D.png" rel="noreferrer"><img src="https://i.sstatic.net/FIa0D.png" alt="29119" /></a>
  <a href="https://i.sstatic.net/ZTcBy.png" rel="noreferrer"><img src="https://i.sstatic.net/ZTcBy.png" alt="29120" /></a></p>
  <p>In fact, those parts can be used to fill both sides of this part at once:</p>
  <p><a href="https://i.sstatic.net/jziBD.png" rel="noreferrer"><img src="https://i.sstatic.net/jziBD.png" alt="Corner with 29119/29120" /></a></p>
  <p>There are plenty of ways to use this part, either by integrating with other slopes, or arranging it using SNOT techniques. For example, here's a quick window that I made to demonstrate how these can be combined to create a nearly circular outline:</p>
  <p><a href="https://i.sstatic.net/snA84.jpg" rel="noreferrer"><img src="https://i.sstatic.net/snA84.jpg" alt="Window design" /></a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-01-15T16:53:22.790Z
Answers.LastActivityDate: 2024-01-15T16:53:22.790Z
Answers.UserDisplayName: jncraton
Body: <p>I recently came across this LEGO part:</p>
  <p><a href="https://i.sstatic.net/qlnW8.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qlnW8.png" alt="Part photo" /></a></p>
  <p>What part is this? What can it be used for?</p>
  
Tags: <part-identification><piece-information><piece-usage>
Title: What is this 2x2 part with one corner curved up?
UserDisplayName: jncraton
ThreadText: # What is this 2x2 part with one corner curved up?
  
  (Asked by: username_0 on 2024-01-15)
  
  I recently came across this LEGO part:
  
  [![Part photo](https://i.sstatic.net/qlnW8.png)](https://i.sstatic.net/qlnW8.png)
  
  What part is this? What can it be used for?
  
  **Tags:** part-identification, piece-information, piece-usage
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2024-01-15. Score: 9
  
  The part is [Plate Special 2 x 2 with Double Inverted Curve, 1 Stud (4190)](https://rebrickable.com/parts/4190/plate-special-2-x-2-with-double-inverted-curve-1-stud/).
  
  [![Part render](https://i.sstatic.net/CVXIY.png)](https://i.sstatic.net/CVXIY.png)
  
  It was introduced in a few sets in 2023. It's original use was to provide an upward curve on roofs. This can be seen very easily in [Himeji Castle (21060)](https://rebrickable.com/sets/21060-1/himeji-castle/):
  
  [![Himeji Castle](https://i.sstatic.net/0Iyvz.png)](https://i.sstatic.net/0Iyvz.png)
  
  It can of course be used for many other things. Trivially, these parts can be tiled to create small peaks in a 4x4 area:
  
  [![4x peak](https://i.sstatic.net/pckNX.png)](https://i.sstatic.net/pckNX.png)
  
  These parts are also compatible with some of the other recent inverted curved slope elements. For example, here it is next to [Brick Curved, Internal Double, 3 x 3 with 1/3 Inverted Cutout, Corner (73682)](https://rebrickable.com/parts/73682/brick-curved-internal-double-3-x-3-with-13-inverted-cutout-corner/):
  
  [![Profile comparison 3x3 Curved Slope Double 73682](https://i.sstatic.net/uPki5.png)](https://i.sstatic.net/uPki5.png)
  
  This is the same profile as [Brick Curved, 3 x 1 with 1/3 Inverted Cutout(70681)](https://rebrickable.com/parts/70681/brick-curved-3-x-1-with-13-inverted-cutout/):
  
  [![Profile comparison 1x3 Arch Inverted 70681](https://i.sstatic.net/8ABEQ.png)](https://i.sstatic.net/8ABEQ.png)
  
  This curve also aligns perfectly with the curve of the [telephone bow](https://rebrickable.com/parts/93273/slope-curved-4-x-1-double-with-no-studs/), assuming that is can be inverted:
  
  [![93273 render](https://i.sstatic.net/v1ZMy.png)](https://i.sstatic.net/v1ZMy.png)
  
  Here's one way those parts can be used together:
  
  [![Telephone bow compatibility](https://i.sstatic.net/T388K.png)](https://i.sstatic.net/T388K.png)
  
  [![Telephone bow front](https://i.sstatic.net/a8zlq.png)](https://i.sstatic.net/a8zlq.png)
  
  Because the telephone lines up with a pair of these, the [2x1 bow slope](https://rebrickable.com/parts/11477/slope-curved-2-x-1-no-studs-12-bow/) also lines up easily:
  
  [![11477 Render](https://i.sstatic.net/IGjSb.png)](https://i.sstatic.net/IGjSb.png)
  
  The notched variant (29119/29120) of those slopes are also compatible:
  
  [![29119](https://i.sstatic.net/FIa0D.png)](https://i.sstatic.net/FIa0D.png)
  [![29120](https://i.sstatic.net/ZTcBy.png)](https://i.sstatic.net/ZTcBy.png)
  
  In fact, those parts can be used to fill both sides of this part at once:
  
  [![Corner with 29119/29120](https://i.sstatic.net/jziBD.png)](https://i.sstatic.net/jziBD.png)
  
  There are plenty of ways to use this part, either by integrating with other slopes, or arranging it using SNOT techniques. For example, here's a quick window that I made to demonstrate how these can be combined to create a nearly circular outline:
  
  [![Window design](https://i.sstatic.net/snA84.jpg)](https://i.sstatic.net/snA84.jpg)
  
  
  ---
  
  