Open your file, Select All and go into Properties. Once there, set the Surface Options to 90.
To keep from having to do this in the future, open a new file and invoke the 3D / Box command. Before you click on the Workspace to define it, go into Properties (Ctrl-F is the quickest way), find the Surface Options and set the value to 90 (or whatever you decide to use). This will re-define the default value used by TurboCAD when you create any more Boxes (and probably other Surface objects, too, but I have Pro, so I can't tell you for certain). Finish creating the Box.
Note that these re-definitions are temporary. They will last only until you change them, or close this TurboCAD data file (they won't even apply to new windows that you open), but we'll fix that in a minute.
Also, invoke the Dimension function for each of the types of measurements that you make and, also before clicking on the Workspace, specify the desired options (Text and Arrow sizes, Resolution, etc.) and then make some measurements.
It would also be a good idea to set up your lights, too, if you use them. My templates have Title Blocks in Paper Space to save time, too.
Now that you have everything set up, delete the objects and Save as Template (give it some memorable name).
When you Open a new file, choose New from template and specify your preferred file.
You'll want to look into saving this Template file as a backup so that you can add it to new installations should the import function fail.
TC Pro Platinum 2018, 2017, 2016 & 2015 (all with LightWorks & RedSDK) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1