a circular ground whose radius is 15 metres , has a 1.2 metre - broad garden around it . what is the area of the garden in square metres ?
req . area = ï € [ ( 16.2 ) 2 â € “ ( 15 ) 2 ] = 22 â  „ 7 ã — ( 31.2 ã — 1.2 ) [ since a 2 - b 2 = ( a + b ) ( a - b ) ] = ( 22 ã — 31.2 ã — 1.2 ) / 7 = 117.67 sq m answer c
subtract(circle_area(add(15, 1.2)), circle_area(15))