Questions in trigonometry

Select	Question
	If in a triangle ABC, a, b, c and angle A is given and $c\sin A
	In a $\Delta ABC,\,\,{{a}^{2}}\sin \,\,2C+{{c}^{2}}\sin 2A=$
	In $\Delta ABC,$ ${{a}^{2}}+{{b}^{2}}+{{c}^{2}}=ac+ab\sqrt{3},$ then triangle is
	The area of triangle $ABC,$ in which $a=1,\ b=2$ , $\angle C=60{}^\circ $ is
	In a triangle $ABC$ , if $b+c=2a$ and $\angle A=60{}^\circ ,$ then $\Delta ABC$ is
	If in a $\Delta ABC$ , the altitudes from the vertices A, B, C on opposite sides are in H.P. then $\sin A,\,\sin B,\sin C$ are in
	If a, b and c are the sides of a triangle such that ${{a}^{4}}+{{b}^{4}}+{{c}^{4}}=2{{c}^{2}}({{a}^{2}}+{{b}^{2}})$ then the angles opposite to the side C is
	In a $\Delta ABC$ if the sides are $a=3,\,b=5$ and $c=4$ , then $\sin \frac{B}{2}+\cos \frac{B}{2}$ is equal to
	Which of the following is true in a triangle ABC
	If the line segment joining the points $A(a,\,b)$ and $B(c,\,d)$ subtends an angle $\theta $ at the origin, then $\cos \theta $ is equal to