Answer:
21.1 yd
Explanation:
The picture above is a triangle and a triangle has 3 sides. The perimeter of the triangle is the sum of the length of the whole sides. The height of the triangle, represented by a dash thin line is just an arbitrary line to estimate the height of the triangle.
side1 = 9 yard
side2 = 5 yard
side3 = 7.1 yard
The perimeter of the triangle is the sum of the sides of the triangle.
perimeter = side1 + side2 + side3
perimeter = 9 + 5 + 7.1
perimeter = 21.1 yard