Yes.
A polygon is a plane figure bounded by a finite number of straight lines. To enclose an area then a minimum of three straight lines are required. All triangles, not just isosceles triangles, are polygons.
Triangle, square and hexagon
An isosceles triangle and an equilateral triangle
Equilateral triangle, square and regular hexagon.
From a distance a cone looks like an isosceles triangle.
a plane triangle is a normal triangle, like the isosceles, right angled, equilateral and scalene triangle.
A polygon is a plane figure bounded by a finite number of straight lines. To enclose an area then a minimum of three straight lines are required. All triangles, not just isosceles triangles, are polygons.
Triangle, square and hexagon
An isosceles triangle and an equilateral triangle
Equilateral triangle, square and regular hexagon.
Equilateral triangle, square and regular hexagon.
From a distance a cone looks like an isosceles triangle.
It works out as an isosceles triangle
A right triangle that is also isosceles cannot have an angle of 57 deg 24 sec unless it is in spherical - as opposed to plane, or flat - space.
isosceles * * * * * In the Euclidean plane such a triangle could not exist, because the sum of its angles exceeds 180 degrees.
equilateral triangle (and so, if it is in Euclidean (plane) space, it has 3 angles all of which are 60°) otherwise (in Hyperbolic or Spherical space) it is an isosceles triangle.
If it's interior angle is a factor of 360 then it will tessellate such as a square, a regular hexagon and an equilateral triangle.