Q126 of 158 Page 159

Find the value of x in Fig. 6.38.

Formula Used/Theory:-


→ Exterior angle is equal to sum of interior opposite angles


In Δ ABC


When BC extended to D


Exterior angle ACD = ∠CAB + ∠ABC


∠ACD = 80° + 30° = 110°


∠ACD = ∠ACE + ∠ECD (As given in figure)


∠ACD = x + 90°


⇒ 110° = x + 90°


x = 110° - 90°


= 20°


Result:- The value of x comes out to be 20°


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