Symmetric point on involute gear

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I have to measure an angle that is created from 3d line using symmetry point on a teeth to the centre point of the gear.But my teeth is not orthogonal to my alignment axis infact it is in 10degree angle. I don't have cad model,so i can't use space point ant it is not a plane surface don't think plane point will work.
I created the symmetric point as usual and changed the points into polar co-ordinate inside the strategy, then give equal radius and z height, how can I control the vectors,i can change the i j k values approximately... Is there is any precise method.
I want to check close angle so my radius correct is important.
My customer is not supporting self centring even though I tried it but it's vectors also going in different directions...
Any suggestions...