Finding area of triangle
Last updated at April 16, 2024 by Teachoo
Ex 10.1, 3 There is a slide in the park. One of its side walls has been painted in the same colour with a message “KEEP THE PARK GREEN AND CLEAN” (see the given figure). If the sides of the wall are 15m, 11m, and 6m, find the area painted in green colour. Area of triangle = √(s(s−a)(s−b)(s −c)) Here, s is the semi-perimeter, and a, b, c are the sides of the triangle Given sides of triangle 15 m, 6m , 11 m So, a = 15 m, b = 6m , c = 11 m s = (𝑎 + 𝑏 + 𝑐)/2 Area of triangle = √(𝑠(𝑠 −𝑎)(𝑠 −𝑏)(𝑠 −𝑐)) Putting a = 15 m, b = 6m , c = 11 m , s = 16 m =√(16(16−11)(16−6)(16−15)) m2 = √(16×5×10×1) m2 = √16×√(5×10) m2 = √16×√(5×5×2) m2 = √16×√(5×5) " "×√2 m2 = √42×√52 " "×√2 m2 = 4 × 5 ×√2 m2 = 20 √2 m2 Therefore, the area painted in colour is = 20 √2 m2 .