Consider the following figure.
It is given that ⟷PB and ⟷RC are parallel lines. Find x
90°
∠ ARO = ∠ CRY = 55∘ (vertically opposite angles)
∠ TPB = ∠ OAR = 35∘ (corresponding angles)
Also, in ΔOAR, we have, x + ∠ ARO + ∠ TPB = 180∘
x = 180∘ - (55∘ + 35∘)
= 90∘