角DAC=β-αAC=(a * sin α)/sin(β-α)又因为角ABC为直角所以AB=AC*sin β=(a * sin α * sin β)/sin(β-α)图的α<β啊?suppose: CB = x, AB=y;since 角ABC为直角:tgα =y/(a+x);tgβ=y/x;then: y = a*tgα*tgβ/(tgβ -tgα );
