Question

triangular sign on the dustbin staying 'WET WASTE' is pasted. Find the area of the triangle whose perimeter is 180cm and two of its sides are 80cm and 18cm. What is the value depicted by the sign. *



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Answer 1

Given,

The perimeter of the triangle = 180 centimetres

The two sides of the triangle = 80 centimetres and 18 centimetres.

To find,

The area of the triangle.

Solution,

First of all we need to find the sum of two sides of the given triangle.

Sum of two sides = (80+18) = 98 cm

Now,we have to find the length of the third side by using the following mathematical formula,

Third side = Perimeter - Sum of two sides = (180-98) = 82 cm

Now,we can easily calculate the area of the given triangle,by the Heron's formula of half perimeter.

Half perimeter = 180/2 = 90 metres

Area = ✓90 × (90-82) × (90-80) × (90-18) = ✓90×8×10×72 = ✓518400 = 720 m²

Hence,the area of the given triangle is 720 m².