Question 1117508
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1.  The answer by @Shin is irrelevant, wrong and incorrect, since it does not take into account that the triangle is SPHERICAL.



2.  The formulation of the problem, in order to be precise, must say which spherical angle of A, B and C is the right spherical angle.



    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>It does not follow from the given data</U>.