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

If one side of a triangle is double the other, and the angles on opposite sides differ by 60^0, then the triangle is equilateral (b) obtuse angled (c) right angled (d) acute angled

If cos^2A+cos^2B+cos^2C=1,t h e n A B C is (a)equilateral (b) isosceles (c)right angles (d) none of these

Angle in major segment . . . .. a. An acute angle b. An obtuse angle c. Right angle d. Reflex angle

If r_1=r_2+r_3+r prove that the triangle is 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)acute angled b)right angled c)obtuse angled d) sinA+cosA = ((a+b))/c

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

In acute angled triangle ABC prove that tan ^(2)A+tan^(2)B+tan^(2)Cge9 .

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

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

x+y=7 and a x^2+2h x y+a y^2=0,(a!=0) , are three real distinct lines forming a triangle. Then the triangle is (a) isosceles (b) scalene (c) equilateral (d) right angled