The triangle formed by the pair of lines 11x2+16xy−y2=0 and x−2y+13=0 is

The combined equation of pair of lines passing through the origin and forming equilateral triangle with the line ax+by+c=0 is ax+by2−3bx−ay2=0 The combined equation of pair of lines passing through the origin and forming equilateral triangle with the line x−2y+13=0 is x−2y2−32x+y2=0 Simplifying the above equation, we get 11x2+16xy−y2=0Therefore, the triangle formed by the given lines is equilateral triangle.