Question

lf the sides of a triangular plot is in ratio 3 : 5 : 7 with its perimeter 300 cms. Find area of triangular plot.​

Answer 1

Answer:

Let the each side be x CM

first side= 3x

second side=5x

third side=7x

perimeter=300 cms

perimeter= first side+ second side+ third side

300=3x+5x+7x

300=8x+7x

300=15x

x=300/15=20

x=20

first side=3x=3*20=60

second side=5x=5*20=100

third side=7x=7*20= 140

Hence all sides are 60,100,140.

Answer 2

$\huge\bold\red{Solution:}$

Suppose that the sides,in metres, are:

• 3x
• 5x
• 7x

Then, we know that 3x+5x+7x = 300 (Perimeter of the Triangle).

Therefore, 15x = 300,which gives x = 20.

So the sides of the triangle are

• 3×20m = 60m
• 5×20m = 100m
• 7×20m = 140m

$\bold\blue{Using\:Heron's\:formula\::-}$

We have s = $\dfrac{60+100+140}{2}m=150m$

&

Area = $\sqrt{150(150-60)(150-100)(150-140)}=150m^2$

=$\sqrt{150\times90\times50\times10m^2}$

=1500$\sqrt{3}m^2$