If ` vec xa n d vec y` are two non-collinear vectors and `A B C` isa triangle with side lengths `a ,b ,a n dc` satisfying `(20 a-15 b) vec x+(15b-12 c) vec y+(12 c-20 a)( vecx xx vec y)=0,` then triangle `A B C` is a. an acute-angled triangle b. an obtuse-angled triangle c. a right-angled triangle d. an isosceles triangle

If vec xa n d vec y are two non-collinear vectors and a, b, and c represent the sides of a A B C satisfying (a-b) vec x+(b-c) vec y+(c-a)( vec x xx vec y)=0, then A B C is (where vec xxx vec y is perpendicular to the plane of xa n dy ) a. an acute-angled triangle b. an obtuse-angled triangle c. a right-angled triangle d. a scalene triangle

Can an equilateral triangle be a, an acute-,b. a right-, and c. an obtuse-angled triangle ? What about isosceles and scalene triangles ?

In a triangle A B C\ a : b : c=sqrt(3)\ :1\ :\ 1, then the triangle is- right angled triangle (b) abtuse angled triangle acute angled triangle, which is not isosceles Equilateral triangle

If in a triangle ABC, tanA+tanB+tanC>0 the triangle is (A) acute angled triangle (B) obtuse angled (C) right angled (D) none of these

A triangle whose one angle is more than 90^0 is called (a) a scalene triangle (b) a right triangle (c) an acute triangle (d) an obtuse triangle

In A B C , if r\ : r_1: R=2\ : 12\ :5, where all symbols have their usual meaning, then A B C is an acute angled triangle A B C is an obtuse angled triangle A B C is right angled which is not isosceles A B C is isosceles which is not right angled

If one angle of a triangle is equal to the sum of the other two angles, then the triangle is (a) an isosceles triangle (b) an obtuse triangle (c) an equilateral triangle (d) a right triangle

The position vectors of the vertices A ,Ba n dC of a triangle are three unit vectors vec a , vec b ,a n d vec c , respectively. A vector vec d is such that vecd dot vec a= vecd dot vec b= vec d dot vec ca n d vec d=lambda( vec b+ vec c)dot Then triangle A B C is a. acute angled b. obtuse angled c. right angled d. none of these

The points (-a ,-b),(a , b),(a^2,a b) are (a) vertices of an equilateral triangle (b) vertices of a right angled triangle (c) vertices of an isosceles triangle (d) collinear

Let a,b,c denote the lengths of the sides of a triangle such that ( a-b) vecu + ( b-c) vecv + ( c-a) (vecu xx vecv) = vec0 For any two non-collinear vectors vecu and vecu ,then the triangle is