Answer:
[tex]2x^2+5x+5[/tex]
Step-by-step explanation:
[tex]\text{You just need to express the perimeter of the triangle in terms of }x.\\\\\text{The perimeter of a triangle is given by the sum of its three sides, therefore, }\\\\\text{Perimeter of triangle = }(x^2+3x)+(2x+1)+(x^2+4)=2x^2+5x+5\\\\\text{So, }2x^2+5x+5\text{ is the required polynomial that represents the perimeter of}\\\text{the triangle.}[/tex]
