For an equilateral triangle, all three sides are equal in length. To find the side length when the perimeter is at least 27 feet, we can set up an equation:

Let $s$ be the length of each side. The perimeter $P$ of an equilateral triangle is given by: $P = 3s$ Since the perimeter must be at least 27 feet, we write: $3s \geq 27$ Solving for $s$: $s \geq \frac{27}{3} = 9$

So, each side must be at least 9 feet long.

Would you like further details or have any other questions?

Here are 5 related questions to expand your understanding:

1. What is the formula for the area of an equilateral triangle?
2. If the side length is 9 feet, what would be the height of the triangle?
3. How does the perimeter of a triangle change if you double the side length?
4. Can an equilateral triangle have a side length smaller than 9 feet for a perimeter of 27 feet?
5. How would the perimeter change if the side length were increased by 50%?

Tip: For equilateral triangles, knowing the side length lets you easily calculate both the perimeter and the area using simple formulas!