Question

in the figure AB equal to AC and angle ACD equal to 115 degree find angle A​

Answer 1

Answer

Correct option is

A

50

0

In △ABC,

∠ACD+∠ACB=180 (Linear pair)

115+∠ACB=180

∠ACB=180−115=65

∘

Now, since, AC=AB

∠ABC=∠ACB=65

∘

(Isosceles triangle property)

Sum of angles of triangle = 180

∠BAC+∠ABC+∠ACB=180

∠BAC+65+65=180

∠BAC=50

∘

Answer 2

Answer:

Adjacent ∠ to 115° + 115° = 180°

⇒ ∠ ACB + 115° = 180°

⇒ ∠ACB = 180° - 115°

⇒ ∠ACB = 65°

As AC = AB ⇒ ∠ACB = ∠ABC

⇒ ∠ABC = 65°

In any triangle sum of all angles is 180°

⇒ ∠ABC + ∠ACB + ∠BAC = 180°

⇒ 65° + 65° + ∠BAC = 180°

⇒ 130° + ∠BAC = 180°

⇒ ∠BAC = 180° - 130°

⇒ ∠BAC = 50°

Step-by-step explanation:

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