# Calculating angles between 2 faces?

**URL:** <https://discourse.shapr3d.com/t/calculating-angles-between-2-faces/1305>\
**Category:** Modeling Questions\
**Created:** [July 20, 2017, 1:51pm UTC](https://discourse.shapr3d.com/t/calculating-angles-between-2-faces/1305 "2017-07-20T13:51:49Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![jay](https://avatars.discourse-cdn.com/v4/letter/j/ed8c4c/32.png) [@jay](https://discourse.shapr3d.com/u/jay)\
**Post date:** [July 20, 2017, 1:51pm UTC](https://discourse.shapr3d.com/t/calculating-angles-between-2-faces/1305/1 "2017-07-20T13:51:49Z")

</div>

Hi everyone,

I’m sketching out a timberframe hip roof and trying to use Shapr3D to better understand some of the angles and cuts. I’ll often extrude dimensional lumber in common sizes, rotate it to where I want it, then start to cut away at it in Shapr3D. Is there a way to calculate the angles between 2 faces?

Also, is there a way to rotate an object relative to itself, rather than relative to the environmental planes? For example, I might want to rotate something around a face rather than an edge, if I rotate something X and Z by 45°, it starts to get tricky to know it’s current orientation for a free form rotation since I can only rotate on one plane at a time.

![](https://cdck-file-uploads-us1.s3.dualstack.us-west-2.amazonaws.com/flex002/uploads/shapr3d/original/2X/e/e77f818164961e0ab29ddbca30e5a38ac785fda1.jpg)