【单选题】84 / 390坦三心圆拱与尖三心圆拱半径关系正确的是?A坦三心圆拱 r1>r2r_1>r_2r1>r2,尖三心圆拱 r2>r1r_2>r_1r2>r1正确B坦三心圆拱 r2>r1r_2>r_1r2>r1,尖三心圆拱 r1>r2r_1>r_2r1>r2C二者均要求 r1=r2r_1=r_2r1=r2D二者均要求 r1=0r_1=0r1=0参考答案A参考解析坦:r1>r2r_1>r_2r1>r2;尖:r2>r1r_2>r_1r2>r1。