Question

find the cost of laying grass in a triangle field of sides 50m,65m,&65m at the rate of rs.7per m square

Answer 1

Semi perimeter=(a+b+c)/2
=180/2=90  m.
Area:$\sqrt{s(s-a)(s-b)(s-c)}$
⇒$\sqrt{90(90-65)(90-65)(90-50)}$
⇒$\sqrt{90*25*25*40}$
=$\sqrt{5 ^{6}*2 ^{4} *3^{2} }$
⇒$125*4* 3$
⇒$1500 m2$
Cost:1500*7
=Rs.10500
Ans:Rs.10500.

Answer 2

Answer:

Rs.10500

Step-by-step explanation:

Sides of triangle :

a = 50 m

b =65 m

c = 65 m

To calculate the area of given triangle we will use the heron's formula :

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

Where $s = \frac{a+b+c}{2}$

a,b,c are the side lengths of triangle  

Now substitute the values :

$s = \frac{50+65+65}{2}$

$s =90$

$Area = \sqrt{90(90-50)(90-65)(90-65)}$

$Area = 1500$

Thus The area of the triangular field is 1500 square m

Now cost of laying 1 sq.m. = rs.7

So, cost of laying 1 sq.m. = $1500 \times 7=10500$

Hence the cost of laying the triangular field is Rs.10500