#### Answer

$12x^2+8x+5$

#### Work Step by Step

Adding all the side measurements, then the perimeter of the given triangle is \begin{array}{l}\require{cancel}
(4x^2+2)+(6x^2+5x+2)+(2x^2+3x+1)
\\\\=
4x^2+2+6x^2+5x+2+2x^2+3x+1
\\\\=
(4x^2+6x^2+2x^2)+(5x+3x)+(2+2+1)
\\\\=
12x^2+8x+5
.\end{array}