NCERT Class 9 Maths Chapter 10 Heron's Formula Solutions
NCERT Class 9 Maths Chapter 10 Heron's Formula Solutions Exercise 10.1 Q.1. A traffic 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? Ans: ‘a’ = a ‘b’ =a ‘c’ = a ∴ Area of the signal board Perimeter = 180 cm ∴ Area of the signal board Alternatively, Area of the signal board Q.2. The triangular side walls of a flyover have been used for advertisement. The sides of the walls are 1200 m, 22m and 120 m (see figure). The advertisements yield an earning of Rs. 5000 per m 2 per year. A company hired one of its walls for 3 months. How much rent did it pay? Ans: a = 122m b = 22m c = 120m 1 year = 12 months ∵ Rent for 12 months per m²= Rs. 5000 ∴ Rent for 3 months of 1320 m²= Rs(1250x 1320) =Rs.1650000. Q.3. There is a slide in a park. One of its side walls has been painted in some colour with a mess...