The diameter of a circular park is 84m . On its outside , there a 3.5 m wide road. Find the cost of constructing the road at ₹ 240 per m²
Answers
Cost of constructing the road at ₹240 per m² is ₹153144
Step-by-step explanation:
GIVEN
Radius of a circular park = 84 m
Radius of road including outside road of a circular park = 84 m + 3.5 m = 87.5 m
Cost of constructing the road = ₹240 per m²
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TO FIND
Cost of constructing the road at ₹240 per m²
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Area of a circular park
We know that,
Area Of Circle = π × r²
Area Of Circle = 22/7 × 84²
Area Of Circle = 22/7 × 7056
Area Of Circle = 22 × 1008
Area Of Circle = 22176
Area Of Circle = 22176 m²
Area of a circular park is 22176 m²
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Area of road including outside road of a circular park
We know that,
Area Of Circle = π × r²
Area Of Circle = 22/7 × 87.5²
Area Of Circle = 22/7 × 7259.04
Area Of Circle = 22 × 1037.00571
Area Of Circle = 22814.1256
Area Of Circle = 22814.1 m²
Area of road including outside road of a circular park is 22814.1 m²
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Cost of constructing the road
We know that,
Cost of constructing the road = 240 × ( Area of road including outside road of a circular park - Area of a circular park
Cost of constructing the road = 240 × ( 22814.1 - 22176 )
Cost of constructing the road = 240 × 638.1
Cost of constructing the road = 153144