Find the perimeter of an equilateral triangle whose side length is 4 cm.

To solve this problem, you will not need the following formulas:

The formula for the perimeter of a triangle is: P = a + b + c, where a, b, c are the sides of the triangle.

The formula for the perimeter of an equilateral triangle: P = a + a + a, where a is the side of an equilateral triangle.

Let’s use the formula for finding the perimeter of an equilateral triangle and substitute in it known quantities such as side a = 4 cm, then we get:
P = a + a + a = 4 cm + 4 cm + 4 cm = 12 cm.

Answer: the perimeter of an equilateral triangle is 12 cm.