If the lengths of the sides of triangle are $$3, 5, 7$$ then the largest angle of the triangle is

In a triangle $$ABC$$, angle $$A$$ is greater than angle $$B$$. If the measures of angles $$A$$ and $$B$$ satify the equation $$3{\mathop{\rm sinx}\nolimits} - 4si{n^3}x - k = 0,$$ $$0 < k < 1$$, then the measure of angle $$C$$ is

From the top of a light-house 60 metres high with its base at the sea-level, the angle of depression of a boat is $${15^ \circ }$$. The distance of the boat from the foot of the light house is

If the bisector of the angle $$P$$ of a triangle $$PQR$$ meets $$QR$$ in $$S$$, then