In the figure, two straight lines PQ and RS intersect each other at O. If ∠POT=75∘, find the values of a, b and c. [4 MARKS]
Concept: 1 Mark
Application: 1.5 Marks
Answer: 0.5 Mark each
ROS is a straight line.
∠ROP+∠POT+∠TOS=180∘
4b+75∘+b=180∘
5b+75∘=180∘
5b=180∘−75∘
b=21∘
Since,PQ and RS intersect at O.
∠QOS=∠POR [Vertically opposite angles]
a=4b
a=4×21∘=84∘
∠ROQ=∠POS (vertically opposite angles)
2c=75∘+b
2c=75∘+21∘
2c=96∘
c=48∘