Fig 3
In Fig. 6.33, PQ and RS are two mirrors placed
parallel to each other. An incident ray AB strikes
the mirror PO at B, the reflected ray moves along
the path BC and strikes the mirror RS at C and
again reflects back along CD. Prove that
ABICD
Fig. 63
Answers
Answer:PLS MARK AS BRANLEST
Step-by-step explanation: Let draw BM ⊥ PQ and CN ⊥ RS.
Given that PQ || RS so that BM || CN
Use the property of Alternate interior angles
∠2 = ∠3 … (1)
∠ABC = ∠1 + ∠2
But ∠1 = ∠2 so that
∠ABC = ∠2 + ∠2
∠ABC = 2∠2
Similarly
∠BCD = ∠3 + ∠4
But ∠3 = ∠4 so that
∠ BCD = ∠3 + ∠3
∠ BCD = 2∠3
From equation first
∠ABC = ∠DCB
These are alternate angles so that AB || CD
Hence proved
Answer:
Step-by-step explanation:
PQ || RS ⇒ BL || CM
[∵ BL || PQ and CM || RS]
Now, BL || CM and BC is a transversal.
∴ ∠LBC = ∠MCB …(1) [Alternate interior angles]
Since, angle of incidence = Angle of reflection
∠ABL = ∠LBC and ∠MCB = ∠MCD
⇒ ∠ABL = ∠MCD …(2) [By (1)]
Adding (1) and (2), we get
∠LBC + ∠ABL = ∠MCB + ∠MCD
⇒ ∠ABC = ∠BCD
i. e., a pair of alternate interior angles are equal.
∴ AB || CD.