Let’s try to write the measurement of the angles from the figure given below:

∠TOS=20°
∠POQ=60°
∠POT=?
∠ROP=?
∠QOS=?
In the above given figure, let us understand the pairs of vertically opposite angle.
∠ROQ is lying opposite to ∠POS.
So, our first pair of vertically opposite angles is ∠ROQ and ∠POS.
∠ROP is lying opposite to ∠QOS.
So, our second pair of vertically opposite angles is ∠ROP and ∠QOS.
Vertically opposite angles are equal.
So ∠ROQ = ∠POS
and ∠ROP = ∠QOS.
Sum of all vertically opposite angles is 360°.
∠ROQ + ∠POS + ∠ROP + ∠QOS = 360°.
Now in the above question,
∠POS = ∠POT + ∠TOS
∠ROQ = 60°.
∠TOS = 20°
So ∠POS = ∠ROQ = 60°.
∠POT = ∠POS - ∠TOS
= 60 – 20
= 40°.
Let ∠ROP = ∠QOS = x [as ∠QOS = ∠ROP……… vertically opposite angles]
So, 60° + 60° + x + x = 360°
120° + 2x = 360°
2x = 360 – 120
2x = 240
x = 240 / 2
x = 120°
So ∠QOS = ∠ROP = 120°.
Couldn't generate an explanation.
Generated by AI. May contain inaccuracies — always verify with your textbook.

