Question

In the given fig. AB=AC and angle ACB = 65° find out the measure of angle BDC

Solve this

Figure is in Attachment.

(hint = answer is 130)

I want answer from Math Aryabhatt​

Answer 1

Hey There

Here's The Answer

_______________________

Given :

• Ang ACB = 65°
• AB = AC

To Find :

• Ang BDC

• In ∆ ABC

=> Ang ACB = Ang ABC

As angles opposite to equal sides are equal, So

=> Ang ABC = 65°

Now,

=> Ang A + Ang ABC + Ang ACD = 180° ( A.S.P. )

=> Ang A + 65° + 65° = 180°

=> Ang A + 130° = 180°

=> Ang A = 180° - 130°

=> Ang A = 50°

• In ∆ ABC and ∆ DCB

=> Ang A = Ang D

( Angles in same segment )

=> Ang D or Ang BDC = 50°

Hence, correct answer is 50°

Note : The answer given in question as a hint is wrong, as if we take ∆ DBC, Angle DBC is supposed to be 130° and Angle DCB should be greater than 65°, Hence it doesn't follow A.S.P.

Hope It Helps.