← The LEGO Parts Guide › Angle › Slope › Inverted Slope

-45° 2×1 Inverted Slope w/ 2-Studs (Part 3665)

1977-2025CURRENT

Custom LEGO part image © 2025 Tom Alphin / Brick Architect.

External Links

LEGO parts are described differently on other websites and may use different part numbers.

LEGO Pick a Brick:
3665 ROOF TILE 1X2 INV.
Bricklink:
3665 Slope, Inverted 45 2 x 1
Rebrickable:
3665 Slope Inverted 45° 2 x 1
3665a Slope Inverted 45° 2 x 1 [Old Type with Small Stud Hole]
Brickset:
3665 ROOF TILE 1X2 INV.
LDraw:
3665a Slope Brick 45 2 x 1 Inverted without Inner Stopper Ring
 CURRENTALL YEARS
OVERALL RANK
-4
73
43
# PIECES
3286(RANK: 92)
14794(RANK: 56)
# SETS
618(RANK: 101)
2697(RANK: 48)
# COLORS
38(RANK: 37)
50(RANK: 36)

Ranking based on buying one copy of every LEGO set, counting the number of sets containing each part, then sorting by part and color.

Overall Rank is a weighted score combining the number of parts, sets, and colors produced.

Current ranking based on sets released between 2021-2025.

Printable LEGO Brick Label

Requires a compatible Brother Label Printer — learn more at brickarchitect.com/labels.

-45° 2×1
Inv. Slope
3665
.LBX

Included in legacy LEGO Brick Labels collection.

-45° 2×1
Inv. Slope
3665
.LBX

Small QR codes are hard to scan with some devices.

Date Added: 2024-02-21 12:00:00

Subscribe for updates!

Join thousands of LEGO fans by subscribing to our monthly newsletter. It contains updates to the LEGO Parts Guide, exclusive subscriber content, and a roundup of the best LEGO news from around the web.

I give Brick Architect consent to send email using the information provided in this form.

What to expect: Brick Architect is committed to respecting your personal data and privacy, in accordance with our Privacy Policy. Please feel free to unsubscribe at any time using the link at the bottom of every email we send.

The LEGO Parts Guide is a work in progress

This is a handcrafted experience to help you browse LEGO parts in a simpler way. If you have ideas to make it better or encounter any issues, please send me an email at tom@tomalphin.com — Thanks!

Check out the About the LEGO Parts Guide page to learn more about why I created this guide. It also includes a detailed version history with images of early prototypes of this guide.


Support the LEGO Parts Guide

The LEGO Parts Guide is an extension of my LEGO Brick Labels project. If you want to support this project and gain access to behind-the-scenes updates, consider supporting the project at patreon.com.

The LEGO Parts Guide © 2025 Tom Alphin / Brick Architect.

Brick Architect earns a commission from qualifying purchases at partner sites such as LEGO.com and Amazon. (For a complete list of affiliate programs, visit About Brick Architect.)

LEGO® is a trademark of the LEGO Group which does not sponsor, authorize or endorse this site. As a member of the Recognized LEGO® Fan Media program, we abide by the LEGO Fair Play and Novelty policies by not sharing leaked photos of unreleased sets.

This guide uses external data from Rebrickable, BrickLink, Brickset, and LDraw.