Use Atan2 for use in astronomy

Good morning,

I have a formula that I want to transcribe from excel to app inventor.
1- I calculate the sin and cos of different angles in degrees (or radian on excel). I have exactly the same results on both when I do "Do It".
2 - I apply the atan2 function on excel which gives me this value
atan2 (-0.24785,0.8976) = 1.8402 or 105.436 degrees
3 - If I do it under app inventor I have -15.437 degrees or -0.26944 rad.
4 - Why when I apply the same values I don't have the same result.
Can you help me ? My application is used to convert equatorial coordinates into Az-Alt coordinates.
I leave you my code.
TempsDePoseAstro.aia (14.6 KB)

This example shows how to use atan2 with App Inventor HOW TO: Plot Sunrise/Sunset line on a Map and learn how to use equations .

OK i see my error thank

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