A triangle as no other 2d shape can have 3 sides.
A shape with four sides has four vertices and a shape with three sides has three vertices, so a shape with four sides has more vertices than a shape with three sides.
Definately a triangle
Assuming that each vertex is used to connect exactly two sides, all two-dimensional shapes will have the same number of sides as vertices. So a shape with 4 sides will have 4 vertices and a shape with 3 sides will have 3 vertices. Think of a square (4 sides, 4 vertices) and a triangle (3 sides, 3 vertices).
A 4 sided shape has 4 vertices whereas a 3 sided shape has 3 vertices.
need to see a pic of a shape with 4 sides and 3 vertices can you supply one
One answer is triangle
A 4 sided shape which is a quadrilateral has more vertices than a 3 sided shape which is a triangle
A shape with four sides has more vertices because there are more points where edges (straight lines) meet than a 3-sided shape.