Question

the primeter of a triangle ground is 900find it's sides in ration 3:5:4using h. f . find the area of the ground?
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Answer 1

Answer:

Let the sides of the triangle be 5x,7x and 8x

Perimeter of a triangle=sum of all its sides.

⇒900=5x+7x+8x

⇒20x=900

or x=20900=45m

Length of its sides are 5x=2×45=225m; 7x=7×45=315‬m and 8x=8×45=360m

∴ length of its sides are 225m,315m and 360m.

Answer 2

Let the sides are

3x ,4x , 5x

Perimeter=900

$\qquad\quad {:}\longmapsto\sf Semi perimeter=s={\dfrac {900}{2}}=450$

According to Heron 's Formula

$\boxed{\sf s={\dfrac {a+b+c}{2}}}$

Substitute the values

$\qquad\quad {:}\longmapsto\sf {\dfrac {3x+4x+5x}{2}}=450$

$\qquad\quad {:}\longmapsto\sf {\dfrac {13x}{2}}=450$

$\qquad\quad {:}\longmapsto\sf 13x=900$

$\qquad\quad {:}\longmapsto\sf x={\dfrac {900}{13}}$

$\qquad\quad {:}\longmapsto\sf x=69.2$

$\qquad\quad {:}\longmapsto\sf x=69 (Approx)$

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$\qquad\quad {:}\longmapsto\sf 3x=3×69=207$

$\qquad\quad {:}\longmapsto\sf 4x=4×69=276$

$\qquad\quad {:}\longmapsto\sf 5x=5×69=345$

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According to Heron 's Formula

$\boxed{\bf Area=\sqrt {s (s-a)(s-b)(s-c)}}$

Substitute the values

$\qquad\quad {:}\longmapsto\sf Area=\sqrt {450 (450-207)(450-276)(450-345)}$

$\qquad\quad {:}\longmapsto\sf Area=\sqrt {450×243×174×105}$

$\qquad\quad {:}\longmapsto\sf Area=\sqrt {2,244,469,500}$

$\qquad\quad {:}\longmapsto\sf Area=47,375.8$

$\qquad\quad {:}\longmapsto\sf Area=47,375 units {}_{(Approx)}$

$\therefore{\underline{\boxed{\sf Area=47,375units.}}}$