It is the regular 7 sided heptagon whose interior angles are greater than the regular 3 sided triangle
It is the regular heptagon which has the larger interior angle. The rule is that as the number of sides of a regular polygon increases then the external angle decreases while the interior angle increases The summation of the interior and external angleof one vertex is 180 degrees.
Either could have a larger interior angle. If they were regular, then the interior angle of a triangle would be 60 degrees whereas that of a heptagon would be 128.57 degrees. The REGULAR heptagon would have a larger interior angle than a REGULAR triangle.
A heptagon is a seven-sided polygon. It has seven interior angles. If it is a Regular polygon, each interior angle measures approximately 128.57 degrees, to a total of 900 degrees.
If, by longer, you mean larger, the answer is a heptagon.
If they are both regular then the 7 sided heptagon has a larger interior angle than a 3 sided equilateral triangle.
It is 60 degrees.
The smallest regular polygon, an equilateral triangle, has interior angles of 60. A square has interior angles of 90. There can't exist a regular polygon with interior angles of 30.
There is no such polygon.
Any polygon can be regular, but usually it is not.
Only when the polygon is a regular convex polygon. Such as an equilateral triangle, or a square, or a regular pentagon.