If the perimeter of an equilateral triangle is 180 cm. Then its area will be:a. 900 cm2b. 900√3 cm2c. 300√3 cm2d. 600√3 cm2

To solve this problem, we need to know that an equilateral triangle is a triangle in which all three sides are equal.

Step 1: Given that the perimeter of the triangle is 180 cm, we can find the length of one side by dividing the perimeter by 3 (since an equilateral triangle has 3 equal sides). So, each side of the triangle is 180/3 = 60 cm.

Step 2: The formula for the area of an equilateral triangle is (sqrt(3)/4) * side^2.

Step 3: Substituting the side length into the formula gives us the area = (sqrt(3)/4) * 60^2 = (sqrt(3)/4) * 3600 = 900*sqrt(3) cm^2.

So, the area of the triangle is 900*sqrt(3) cm^2, which corresponds to option b.