In Fig. 6.17, POQ is a line. Ray OR is perpendicular to line PQ. OS is another ray lying between rays OP and OR. Prove that∠ ROS =(∠ QOS –∠ POS).
It is given in the question that:
OR is perpendicular to line PQ
To prove,
∠ROS = (∠QOS - ∠POS)
Now, according to the question,
∠POR = ∠ROQ = 90O (Perpendicular)
∠QOS = ∠ROQ + ∠ROS = 90O + ∠ROS (i)
∠POS = ∠POR - ∠ROS = 90O - ∠ROS (ii)
Subtracting (ii) from (i), we get
∠QOS - ∠POS = 90o + ∠ROS – (90o - ∠ROS)
∠QOS - ∠POS = 90o + ∠ROS – 90o + ∠ROS
∠QOS - ∠POS = 2∠ROS
∠ROS = (∠QOS - ∠POS)
Hence, proved