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Class 9 maths NCERT solutions- Heron’s formula

Class 9 maths NCERT solutions-Chapter 12 Heron’s formula To understand this formula better let us go through   Class 9 Maths solutions   Area of a triangle=√s(s-a)(s-b)(s-c) Exercise 1 Question 1 . A traffic signal board, indicating ‘SCHOOL AHEAD’ is an equilateral triangle with side     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? MATHS Question Solution:-Perimeter=sum of all sides = 180=3a =side of a triangle 180/3=60cm =s=180/2=90 = using herons formula =√s (s-a)(s-b)(s-c) =√90(90-60)(90-60)(90-60) =√90*30*30*30 =√3*3*10*3*10*3*10*3*10 =3*3*10*10√3 =900√3cm² Question – Sides of a triangle are in the ratio of 12:17:25 and its perimeter is 540 cm. Find its area? Solution-  Let the ratio b x Perimeter= sum of all sides 540 =12x+17x+25x 540=54x X=540/54=10 Side a =12*10=120 Side b=17*10=170 Side c=25*10=250 S=a+b+c/2=540/2=270 cm Area of a triangle u