Possibly an equilateral triangle
That would be an isosceles triangle
here's one shape,issoleces triangle.(p.s hope i spelt it right!)
1
1
1
1
1
An equilateral triangle has 3 lines of symmetry whereas an isosceles triangle only has 1 line of symmetry and other triangles have no lines of symmetry.
An isosceles triangle has one line of symmetry
Circle, Square, Triangle
It appears to have 1 line of horizontal symmetry