SOLUTION: A triangular park has sides 120 m,50 m and 80 m. Find the area of triangular park. A wire is rotated around the park leaving 3 m area. If cost of 1 m wire is 20 rs, then find the c

Question 985340: A triangular park has sides 120 m,50 m and 80 m. Find the area of triangular park. A wire is rotated around the park leaving 3 m area. If cost of 1 m wire is 20 rs, then find the cost of total wire to be used.
Answer by ikleyn(52781) (Show Source): You can put this solution on YOUR website!

I will answer only the first part of the question regarding the area of the park (the area of the given triangle).

Use the Heron's formula for the triangle area:

= .

named after the ancient Greek mathematician Heron.
Here , and are the measures of a triangle sides and is half of the perimeter: = .

In our case a = 120 m, b= 50 m, and c = 80 m. Hence, the semi-perimeter is

= = =

and the area of the given triangle is

= = = = .. = . = (approximately).

For the Heron's formula see the lessons
    - Formulas for area of a triangle,
    - Proof of the Heron's formula for the area of a triangle and
    - One more proof of the Heron's formula for the area of a triangle
in this site.

RELATED QUESTIONS
Nancy runs around a triangular park of sides 60 m, 50 m, 90 m and Rich runs around a... (answered by richwmiller)

The neighborhood park has a radius of 42 m and a path that is 2 m wide around the park.... (answered by josgarithmetic)

The length of a rectangular park is 4 m longer than the width. If the area of the park is (answered by ichudov)

The sides of a triangular park are 8 m ,10 m and 6 m respectively a small circular area... (answered by Cromlix)

The bredth of a rectangular park is 7 m less than its length. If the perimeter of the... (answered by Cromlix)

The local park measures 60 m by 50 m. Part of the park is torn up to install a sidewalk... (answered by rothauserc,ikleyn)

THERE IS A RECTANGULAR SHAPED PARK AND A CIRCULAR GARDEN INSIDE THE PARK. IF THE LENGTH... (answered by josgarithmetic)

A rectangular park having lenght of 72 m and breadth of 54 m is surrounded by a path of... (answered by checkley77)

A grassy park is 260 m by 170 m. If a square sand pit with sides of 16 m occupies the... (answered by Cromlix)