Perimeter = 36 cm

Heron's formula: Area =

What is the area of an equilateral triangle that has a perimeter of 36 centimeters? Round to the nearest square centimeter.

15 square centimeters

62 square centimeters

72 square centimeters

705 square centimeters

Heron's formula:

Triangle Area = √[s (s-a) (s-b) (s-c) ]

Where s = half of the perimeter of the triangle (in our case = 36/2=18)

a, b, & c the length of each side (in our case all sides are equal since it's an equilateral triangle with a perimeter = 36 or each side = 36/3 = 12)

Now we can apply Heron's formula:

Area = √[18 (18-12) (18-12) (18-12] = √[18x6x6x6] = √ (3888) = 62.354 cm²

or rounded = 62 cm²

Answer is 62 sq. centimeters