In triangle ABC if <A and <B are acute angles and sin 10/13 , what is the value of cos A?

Your 8 answer-mooching posts have been removed.

To quote one of our very good math and science tutors: “You will find here at Jiskha that long series of questions, posted with no evidence of effort or thought by the person posting, will not be answered. We will gladly respond to your future questions in which your thoughts are included.”