sin125/sin55-cos125/cos55=sin125cos55-cos125sin55/sin55*cos55=
2sin(125-55)/sin110=2sin70/sin110=2sin(180-70)/sin110=2sin110/sin110=2
sin125/sin55-cos125/cos55=sin125cos55-cos125sin55/sin55*cos55=
2sin(125-55)/sin110=2sin70/sin110=2sin(180-70)/sin110=2sin110/sin110=2