The Total solution for NCERT class 6-12
In figure, PQ || ABand PR || BC. If ∠QPR = 102°, determine ∠ABC. Give reasons.
Extend line AB to meet line PR at point G.
Given: PQ || AB,
∠QPR = ∠BGR =102°
[Corresponding angles ofparallel lines are equal]
And PR || BC,
∠RGB+ ∠CBG =180°
[Corresponding angles aresupplementary]
∠CBG =180° – 102° = 78°
Since, ∠CBG = ∠ABC
=>∠ABC =78°