#tnnewsyllabus TN Class 9 Maths Mensuration Exercise 7.1 Q.no.1 Chapter 7 Alexmaths Heron’s Formula https://alexmathsonlineeducation.blog... 5. An advertisement board is in the form of an isosceles triangle with perimeter 36m and each of the equal sides are 13 m. Find the cost of painting it at ₹ 17.50 per square metre.