` Delta ABC` में सिद्ध कीजिए कि -
` Delta = (b^(2)-c^(2))/2 * ( sin B sin C)/(sin ( B-C))`

Explanation

` R.H.S = (b^(2)- c^(2))/2 * (sinB sin C)/(sin(B-C))`
` = (k^(2)sin^(2) B-k^(2)sin^(2)C)/2 * (sin B sin C)/(sin(B-C))`
` = (k^(2) (sin^(2) B-sin^(2)C))/2 * (sinB sin C)/(sin (B-C))`
` = (sin(B+C)sin(B-C))/2 * (ksinB* k sinC)/(sin(B-C))`
` =1/2 sin(B+C) * b*c`
` = 1/2 bc* sin (180^(@)-A)`
` = 1/2 bc sin A = Delta = L.H.S`