Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
913 views
in Plane Geometry and Line and Angle by (35.3k points)
closed by

Two plane mirrors PQ and QR are joint together at Q with an angle of 30°. The incident ray AB parallel to the mirror RQ, then find the value of ∠BCQ, ∠CBQ and ∠BDC.

1 Answer

+1 vote
by (34.1k points)
selected by
 
Best answer

BL || CD

∠1 = ∠2 i.e. ∠LBC = ∠BCD

Also CD ⊥ PQ

⇒ ∠CDB = ∠CDQ = 90°

⇒ ∠DCQ = 180° – 120° = 60° = ∠DCB

as CD is bisector ∠BCQ

⇒ ∠BCQ = ∠BCD + ∠DCQ 

= 60° + 60° = 120°

In ∆CBD,

∠CBD + 90° + 60° = 180°

⇒ ∠CBD or ∠CBQ 

= 180° – 150° = 30°

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

...