## MCQ (Single Correct Answer)

If a = 2$$\sqrt2$$, b = 6, A = 45$$^\circ$$, then

In triangle ABC, if $$\sin A\sin B = {{ab} \over {{c^2}}}$$, then the triangle is

In a triangle PQR, $$\angle$$R = $$\pi$$/2. If $$\tan \left( {{P \over 2}} \right)$$ and $$\tan \left( {{Q \over 2}} \right)$$ are roots of ax2 + bx +...

In a right-angled triangle, the sides are a, b and c, with c as hypotenuse, and c $$-$$ b $$\ne$$ 1, c + b $$\ne$$ 1. Then the value of $$({\log _{c +...

If $${{\cos A} \over 3} = {{\cos B} \over 4} = {1 \over 5}, - {\pi \over 2} ...

In a $$\Delta$$ABC, $$2ac\sin \left( {{{A - B + C} \over 2}} \right)$$ is equal to

If in a triangle ABC, sin A, sin B, sin C are in A.P., then

ABC is an isosceles triangle with an inscribed circle with centre O. Let P be the midpoint of BC. If AB = AC = 15 and BC = 10, then OP equals

The three sides of a right angled triangle are in GP (geometric progression). If the two acute angles be $$\alpha$$ and $$\beta$$, then tan$$\alpha$$ ...

The angles of a triangle are in the ratio 2 : 3 : 7 and the radius of the circumscribed circle is 10 cm. The length of the smallest side is

## Subjective

If cos A + cos B + cos C = 0, prove that cos 3A + cos 3B + cos 3C = 12 cos A cos B cos C.