Step 1: Note down the given values and recall the perimeter of the equilateral triangle.

              NOTE: Perimeter of equilateral = 3* a

                          Where a is the side of the equilateral

Step  2: Find the side of the equilateral triangle by using the perimeter formula

                    NOTE:  Perimeter of equilateral = 3* a

                                   a = \frac{Perimeter of equilateral}{3}

                    EXAMPLE: Side a = \frac{30}{3}

                                        Side a = 10 cm

Step 3: Set up a area formula of an equilateral triangle.

NOTE: Equilateral triangle all sides are equal.

Area of equilateral triangle = \frac{\sqrt{3}}{4} a^2

Step 4: Plug in the side (a) value in the area of the equilateral triangle formula

            EXAMPLE: Side a = 10 cm

                                            = \frac{\sqrt{3}}{4} a^2

                                            = \frac{\sqrt{3}}{4} (10)^2

Step 5: Do Some calculations for the required area.

                      EXAMPLE = \frac{\sqrt{3}}{4} (100)

                                        = \sqrt{3}* 25

                                        = 25 \sqrt{3}