We are given a triangle with dimensions of the three sides as :
first side: 10x+3x²-8 feet
second side: 12x feet
third side: (15x+4) feet
Now perimeter of triangle is given by:
Perimeter = sum of three sides
So adding the three sides:
Perimeter = 10x+3x²-8 + 12x +15x+4
combining like terms and simplifying:
Perimeter = 3x²+37x-4
Answer: The perimeter of park will be (3x²+37x-4) feet.