`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 equilateral (d) right angled

The straight lines x+y=0, 3x+y-4=0 and x+3y-4=0 form a triangle which is (A) isosceles (B) right angled (C) equilateral (D) scalene

The pair of straight lines x^(2)-4xy+y^(2)=0 together with the line x+y+4sqrt(6)=0 form a triangle which is: (A) right angled but not isoscles (C) scalene (B) right angled but not equilateral

Centres of the three circles x^2+y^2 - 4x - 6y - 14=0, x^2 +y^2-4x-6y-14=0 and x^2+y^2-10x-16y+7=0(A) are the vertices of a right triangle (B) the vertices of an isosceles triangle which is not regular (C) vertices of a regular triangle (D) are collinear ts inht lines, at right angled to each other.

The straight lines x +y=0, 5x + y= 4 and x+5y=4 form (A) an isosceles triangle (B) an equilateral triangle (C) a scalene triangle (D) a right angled triangle

Prove that the lines y=3x+1,y=4ndy=-3x+2 form an equilateral triangle.

Three lines whose joint equation is 4x^(2)y-y^(3)=0 form a triangle which is