Question

a well of a diameter 150 cm has a 30 cm wide parapet running around it .find the area of parapet

Answer 1

Given, the diameter of the well (d) = 150 cm.

Let radius and diameter of the parapet is R and D respectively.

Sine, length of the outer edge of the parapet = 770 cm.

Therefore,

2πR = 770 cm

2R = 770 / π = (770 x 7 )/22 = 245 cm

D = 245 cm.

Now, width of the parapet = ( diameter of parapet - diameter of the well)/2 = (245 - 150 )/2 = ( 95)/2 =  47.5 cm

Hence, width of the parapet is  47.5 cm.




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