With the usual notations, if the lengths of the sides of the triangle are 3 units, 5 units and 7 units, then the largest angle of the triangle is

In a right-angled $\triangle ABC$, the measures of the angles are in an Arithmetic Progression (A.P.) If its smallest side is $4$ units, then the area of $\triangle ABC$ is.....

In $\triangle ABC$, with usual notations, $(a + b + c)(b + c - a)(c + a - b)(a + b - c) = 3b^2c^2$, then $\angle A = $

If ABC is a triangle of area $\Delta$ with $a = 2, b = \dfrac{7}{2}, c = \dfrac{5}{2}$, where $a, b, c$ are the lengths of the sides of the triangle opposite to angles A, B and C respectively, then $\dfrac{2\sin A - \sin 2A}{2\sin A + \sin 2A}$ is equal to...