Question

13. In the figure (i) given aside DE || AB, ZCAB = 42°
and ZCBA = 35°. Find the values of a and b.
E
b
a
D
C 35º B
​

Answer 1

Answer:

Step-by-step explanation:

Given:

AB||DE, ∠BAC=35∘ &

∠CDE=53∘

∠DEC=∠BAC=35∘ ….(i)    (alternate interior angles)

∠CDE=53∘       ……..(ii)       (given)

 

In, ∆CDE  

∠CDE+∠DEC+∠DCE=180°  

 

[sum of interior angles of a triangle is 180∘.]

 

⇒53∘+35∘+∠DCE=180∘  

⇒88∘+∠DCE=180∘

⇒∠DCE=180∘−88∘=92∘

∠DCE=92°