Question

A square lawn with side 100 m long has a circular flower bed in the centre. if the area of the lawn, excluding the flower bed is 8614 m2, the radius of the circular flower bed is:

Answer 1

Area of circular field=Area of square lawn-Area of lawn excluding circular bed
πr²=100²-8614
(22/7)r²=10000-8614
  r²=1386×7/22
  r²=441
  r=√441
  r=21 m

Radius of the circular bed is 21 m.

Answer 2

Hi !
Here is your answer.

Area of circular bed = A(Lawn) - A(lawn excluding flower bed)
...................................(1)
Now,

we have.........

Side of the lawn = 100m
Area of lawn excluding flower bed = 8614sq.m.

Area of square lawn= (side)^2
= (100)^2 = 10000sq.m.
_________________
A(Lawn) = 10000sq.m.............(2)
_________________

Area of circular bed = πr^2
= 22/7 × r^2
______________________
A(Circular bed) = 22/7×r^2....(3)
______________________

From (1) ,(2) & (3)

22/7 × r^2 = 10000 - 8614

22/7 × r^2 = 1386

22r^2 = 1386 × 7

22r^2 = 9702

r^2 = 9702 / 22

r^2 = 441

[By taking square root to both sides]

r = 21m.
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Final Answer :
The radius of the circular bed is 21m.
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hope this helps ! ! ! #