Tolong ya pake cara di butuh kan secepat nya ​

a.) 180°= 90°+a°+(a+20)°

180°= 2a°+110°

70° =2a°

a = 35°

c.) 180°= (a+20)°+40°+ sdt ROS

180°= (35+20)°+40°+ sdt ROS

180°= 55°+40° +ROS

180°=95°+ROS

ROS= 85°

b.) 180°=40°+ROS+QOR

180°=40°+85°+QOR

180°=125°+QOR

QOR= 55°