CBSE Notes, Lectures

CBSE - Mathematics - Lines and Angles

Lines and Angles

NCERT Exercise Exercise 6.1

It is given that ∠XYZ = 64° and XY is produced to point P. Draw a figure from the given information. If ray YQ bisects ∠ZYP, find ∠XYQ and reflex ∠QYP.

Given,
∠XYZ = 64°
YQ bisects ∠ZYP 

∠XYZ +∠ZYP = 180° (Linear Pair)
⇒ 64° +∠ZYP = 180° 
⇒ ∠ZYP = 116°
also, ∠ZYP = ∠ZYQ + ∠QYP 
∠ZYQ = ∠QYP (YQ bisects ∠ZYP)
⇒ ∠ZYP = 2∠ZYQ 
⇒ 2∠ZYQ = 116°
⇒ ∠ZYQ = 58° = ∠QYP
Now,
∠XYQ = ∠XYZ + ∠ZYQ 
⇒ ∠XYQ = 64° + 58°
⇒ ∠XYQ = 122°
also,
reflex ∠QYP = 180° + ∠XYQ
∠QYP = 180° + 122°
⇒ ∠QYP = 302°

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