A trick I found out for this. When you make the triangle put your curser on the ping it self. If the range is around the same for all three then you got it.
Viewing post in Voices of the Void 0.9.0 feedback
*sigh* yes, I know how to build a triangle like bigger than signal circles, I mean... well, the dev just drop new thing just to increase the difficulties of ping process, but it's not a salvation for problem with boringness of the game.
also we have whole grid to build triangles... infinite power of triangles...)