B点为后视方向，按极坐标法测设A、B两点，试分别计测设数据∠BA1、Da1和∠BA2、Da2。

?XA1?198.324?285.684??87.36m ?YA1?86.425?162.345??75.92m

D22A1??XA1??YA1?115.74m aA1A1?ctg?YX?40059'32''? A1?BA1?aA1?aAB?3600?104°15′02″

?XA2?198.324?285.684??87.36m ?YA2?238.265?162.345?75.92m DA2?115。74m aA2?319°00′28″∠BA2=22°15′28″

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