An equilateral triangle has an apothem measuring 2. 16 cm and a perimeter of 22. 45 cm. An equilateral triangle has an apothem with length 2. 16 centimeters and a perimeter of 22. 45 centimeters. What is the area of the equilateral triangle, rounded to the nearest tenth? 2. 7 cm2 4. 1 cm2 16. 2 cm2 24. 2 cm2.