3.
In the fig, AB || CD,FIND x.(Hint:Prove that AOB-COD).
Answers
Given :- In the fig, AB || CD, FIND x.(Hint:Prove that AOB ~ COD).
Solution :-
in ∆AOB and ∆COD , we have,
→ AB || CD .
So,
→ ∠ABO = ∠CDO { Alternate angles. }
similarly,
→ ∠BAO = ∠DCO { Alternate angles. }
and,
→ ∠AOB = ∠COD { vertically opposite angles. }
Therefore,
→ ∆AOB ~ ∆COD { By AAA similarity. }
Hence,
→ AO / CO = BO / DO { in similar ∆'s , ratio of corresponding sides are equal. }
Putting values now, we get,
→ 4 / (4x - 2) = (x + 1) / (2x + 4)
cross - Multiply,
→ 4(2x + 4) = (4x - 2)(x + 1)
→ 8x + 16 = 4x² + 4x - 2x - 2
→ 4x² + 2x - 8x - 2 - 16 = 0
→ 4x² - 6x - 18 = 0
→ 2(2x² - 3x - 9) = 0
→ 2x² - 3x - 9 = 0
→ 2x² - 6x + 3x - 9 = 0
→ 2x(x - 3) + 3(x - 3) = 0
→ (x - 3)(2x + 3) = 0
Putting both equal to 0, we get,
→ x = 3 or , (-3/2)
since negative value of x is not Possible.
→ x = 3 (Ans.)
Hence, x is equal to 3.
Learn more :-
PQR is an isosceles triangle in which PQ=PR. Side QP is produced to such that PS=PQ Show
that QRS is a right angle
https://brainly.in/question/23326569
In triangle ABC, if AL is perpendicular to BC and AM is the bisector of angle A. Show that angle LAM= 1/2 ( angle B - an...
https://brainly.in/question/2117081
Step-by-step explanation:
...............@..........@.........................