How to measure Vertex Angles

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johnanthony
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Joined: Thu Apr 16, 2020 11:17 am

How to measure Vertex Angles

Post by johnanthony » Thu Apr 16, 2020 11:36 am

Hello - I am a newbie here so I am afraid I will be asking quite a few questions over the next few weeks, please bear with me. :-)

My first question concerns how to measure vertex angles -

What I want to be able to do is look at a vertex, sighting straight through the centre of the polyhedron, and then measure the angles of the edges radiating out from that vertex. Note that these angles are not the internal angles of the surrounding polygons, but the angles that would be measured if those edges were projected onto a plane normal to the line from the vertex to the centre of the polyhedron.

An example would be the truncated cuboctahedron where each vertex is surrounded by a square, hexagon, octagon. Obviously, the angles I am looking for are not 90deg, 120deg, 135deg ... but these angles projected onto the plane normal to the sight line from the vertex to the centre of the polyhedron, and they will of course be larger.

Thanks in anticipation.

John

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robertw
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Re: How to measure Vertex Angles

Post by robertw » Thu Apr 16, 2020 2:08 pm

Hi John,

Yep that can be done.
  • From the menu, enable "Display->Show Vertex Angles"
  • Select a vertex (Either Shift+Left-click, or double-click on a vertex)
It will show angles related to that vertex, like below.

Image

Measurement Mode could be used to measure angles more generally, but is a bit trickier to use, eg:

Image

johnanthony
Posts: 4
Joined: Thu Apr 16, 2020 11:17 am

Re: How to measure Vertex Angles

Post by johnanthony » Thu Apr 16, 2020 2:20 pm

Hello Rob

That was quick, and so easy when you know how! I was expecting to have to measure individual angles, this give me the whole lot in one go ... perfect.

Now I have all the information to build a jig for cutting the compound mitres at the end of wooden edge sticks to create Leonardo models, all from one key-click!

Thanks for that.

John

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