Issues with ArcGIS Pro scaling while creating radius

[GIS412]

Hello. I'm new to Esri products and have  a question.

A user is having problems with arcgis radius scaling. User states that when he is creating 2 radius' that the radius scaling is off by a factor of 1.4. It is the inner circle in the attached image.

Does anyone know where a setting is to fix this? 

[DavidSolari]

This could be an issue with the chosen coordinate system of the data and/or map but we'll need more information. What tool is used to create the circles? How are they entering the desired radius?

[GIS412]

Hello,

I mainly use the Construction line – Water for creating the locations where the Water utilities go.  Once Construction line is selected under Edit, I select the circle icon, type R for radius and enter the value (multiplying by 1.479). 

This is his response.

[DavidSolari]

I created a polygon FC in Web Mercator, then created a 2m radius using the method described around 49N. The resulting circle had a planar diameter of 4m but a geodesic diameter of 2.62m for an error of 1.53x. This seems like the most likely culprit of your error.

[GIS412]

Great explanation! So by the sounds of it, the reason for this discrepancy is that the method in which the user is creating the second radius is setting the measurement as geodesic and not planar?

Is there anyway to change this? Or should the user be using a different method to create the radius? Or is there some setting that allows all radii to be set in planar measurement?