This question is from class 9 maths 12th chapter. the chapter name is herons formula. It is very important question. I want to get the solutions of this question because its very important. In this question they have asked .A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?