Question

prove that in a triangle the angle at a vertex is equal the sum of the inner angles the other two vertices?​

Answer 1

"An exterior ∠ is equal to the addition of the two Δ angles not right next to it.

140º = 60º + 80º;        120º = 80º + 40º;

100º = 60º + 40º

The exterior angle is supplementary to its adjacent Δ angle. 140º is supp to 40º

The 2 exterior angles at each vertex are = in measure because they are vertical angles.

The exterior angles (taken one at a vertex) always total 360º

"

Answer 2

Answer:

already uhhh have Ans ...........