3a portion of an embankment having a uniform upgradient 1 in 500 is circular with radius 1000 m ofthe centre lineit subtends 180° at the centreifthe height of the bank is 1 m at the lower end, andside slopes 2:1, the earth work involved.a 26,000 m3b26,500 m3c27,000 m3d27,500 m3​