A park is in the form of a rectangle 120 m by 90 m. At the centre of the park, there is a circular lawn as shown in the figure. The area of the park excluding the lawn is 2950 m^{2}. Find the radius of the circular lawn. [Given, π = 3.14]

Given:

Length of the rectangular park = 120 m

Breadth of the rectangular park = 90 m

Area of the park excluding the circular lawn = 2950m^{2}

Area of the rectangular park = length × breadth

= 120 × 90

= 10800m^{2}

Area of circular lawn = Area of rectangular park – Area of park excluding the lawn

= 10800 – 2950

= 7850m^{2}

∵ Area of circle = πr^{2}

∴ 7850 = 3.14 × r^{2}

r^{2} = = 2500

r = √2500 = 50 m

__Hence, the radius of the circular lawn is 50m.__

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