Question

Please help me with this question, I am really confused.

Answer 1

Answer:

see the reason it because in a isosceles triangle two angle are equal and one angle is not equal.

In this figure angle A = angle C

Answer 2

Answer:

As we can see that Angle ACD=Angle BAC

(Alternate interior angle)

SO WE CAN COME TO THE CONCLUSION THAT

50°=Angle BAC

NOW ANGLE BAC+ANGLE BCA+ANGLE ABC=180°

so, 50°+80°+Angle BCA=180°

ANGLE BCA=180°-(80°+50°)

=180-130

=50°

Therefore it is an Isosceles Triangle, becuase its base angle are equal...