Math Chapter Wise Properties Of Triangle And Circular Inverse Function English MCQ TGT 1999 Q.In a triangle A, B and C are in A.P. then. Ac2 = a2 +b2 -ab Bb2 = a2 +c2 –ac Cc2 = a2 +b2 DNone of these Show answer Correct answer: b2 = a2 +c2 –ac