In $\triangle ABC$, with usual notation, if $a = 13, b = 14, c = 15$, then the sum of the values of $\sin\left(\dfrac{A}{2}\right)$ and $\sin A$ is....

In $\triangle ABC$, with usual notation, if cot A, cot B, cot C are in arithmetic progression, then

With usual notations, in $\triangle ABC$, if $\cos C = \dfrac{\sin A}{2\sin B}$, then which of the following is true ?

In $\triangle ABC$, if $a = 13, b = 14, c = 15$, then the value of $\sin A + \cos A$ is...