The radius of a circular garden is 84m. inside it there is a 7 metre wide road along its circumference. find the area of this road
Answers
Explanation:
Diameter =84 m, Radius =42 m
Outer radius =42+3.5 m =45.5 m
Outer area from center = πR
2
=3.14×(45.5)
2
=6500.58m
2
Inner area = πr
2
=3.14×42×42
=5538.96m
2
Area of round = (6500.58−5538.96)m
2
=961.62m
2
Cost of construction = Rs. 2.40perm
2
∴ cost of construction = Rs. 2.40×961.62
=Rs.2307.88.
Solution :
Radius of circular garden : 84 m
Width of the road along the circumference of the garden: 7 m
Remaining radii : 77 m
To find : Area of Road
=> Total Area of circular garden - Area of circular garden excluding the road
=> T ( 84 )? - T (77)2
=> TT x ( 161) x 7
=> 22 x 161
=> 3542 m2 .
Answer: The required area of this road is 3542 m2.
Additional Information :
Area of a circle - a r?
Circumference of a circle : 2 ur
Area of a semi circle : ( 180/360) TTr?
Circumference of semi circle : IT r.