Answer:
[tex]2x^{2}+6x[/tex]
Step-by-step explanation:
Perimeter is the distance all round a figure. Given length and width only, then this shale is likely to be a triangle. For a triangle, the area is given by
P=2(l+w)
Where l is the length and w is width.
Substituting w with 3x-4 and l with [tex]x^{2}+4[/tex]
then
[tex]P=2( x^{2}+4 +3x-4)=2( x^{2}+3x)=2x^{2}+6x[/tex]
Therefore, perimeter is [tex]2x^{2}+6x[/tex]