What is the perimeter of an equilateral triangle with each side measuring 18?

To find the perimeter of an equilateral triangle, you add the lengths of all three sides together. In this case, since each side of the triangle measures 18 units, the calculation is straightforward.

You would multiply the length of one side (18) by the number of sides in the triangle (which is always 3 for any triangle):

Perimeter = side length × number of sides

Perimeter = 18 × 3

When you perform this calculation:

18 × 3 = 54

Thus, the perimeter of the equilateral triangle is 54 units, making it the correct answer. This highlights the method for calculating perimeter in cases of regular polygons, where knowing the side length and the number of sides allows for a direct computation.