In `ABC` with usual notations, if `r=1,r_1=7 and R=3,` the `(a) ABC` is equilateral (b) acute angled which is not equilateral (c) obtuse angled (d) right angled

If the sines of the angles A and B of a triangle ABC satisfy the equation c^2x^2-c(a+b)x+a b=0 , then the triangle (a) is acute angled (b) is right angled (c) is obtuse angled (d) satisfies the equation sinA+cosA ((a+b))/c

If in a triangle ABC, a=3, b=5 and c=7, show that the triangle is obtuse angled.

If sinA=sin^2Ba n d2cos^2A=3cos^2B then the triangle A B C is right angled (b) obtuse angled (c)isosceles (d) equilateral

(x) DEF is the pedal triangle of the equilateral Delta ABC. Find angle BED .

If r_1 =r_2+r_3+r, prove that the triangle is right angled.

In triangle ABC, if r_(1) = 2r_(2) = 3r_(3) , then b : c is equal to

If a vertex, the circumcenter, and the centroid of a triangle are (0, 0), (3,4), and (6, 8), respectively, then the triangle must be (a) a right-angled triangle (b) an equilateral triangle (c) an isosceles triangle (d) a right-angled isosceles triangle

In the triangle ABC, if a=5, b=7 and c=3, find the angle B and the circumradius R.

In a triangle A B C , the altitude from A is not less than B C and the altitude from B is not less than A C . (a)The triangle is right angled (b) isosceles obtuse angled (d) equilateral

In triangle ABC, right angled at C, (tanA+tanB) equal to