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The Perimeter of an Isosceles Triangle is 42 Cm and Its BašE is (32) Times Each of the Equal Sides. Find the Length of Each Side of the Triangle, Area of the Triangle and the Height of the Triangle.

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प्रश्न

The perimeter of an isosceles triangle is 42 cm and its baše is (32) times each of the equal sides. Find the length of each side of the triangle, area of the triangle and the height of the triangle.

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उत्तर

Let ‘x’ be the measure of each equal sides

∴ Base =`3/2x`

`∴x + x + 3/2x= 42 `      [∵ Perimeter = a + b + c = 42 cm]

`⇒7/2x=42 `

`⇒x= 12cm`

∴Sides are a = x = 12 cm

b = x = 12 cm

`c=x=3/2(12)cm = 18 cm`

By heron’s formulae

∴ Area of triangle =`sqrt(s(s-a)(s-b)(s-c)) cm^2`

=`sqrt(21(9)(9)(21-18)cm^2)`

=`sqrt((21)(9)(9)(3))cm^2`

=`71.42cm^2`

`∴ Area   of triangle = 71.42 cm^2`

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अध्याय 17: Heron’s Formula - Exercise 17.1 [पृष्ठ ८]

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आर.डी. शर्मा Mathematics [English] Class 9
अध्याय 17 Heron’s Formula
Exercise 17.1 | Q 10 | पृष्ठ ८

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