In this video, let's discuss the anger, some property of a triangle.
Let's take an example of a triangle.
We have Triangle ABC over here.
As for the angles and property, angle it plus angle B plus Anglesey is equal to 180 degrees.
And this is true for any triangle.
Let's see why this is so.
Let's produce B.S. and market point B over here.
Now let's mark the internal angles as well as the exterior angle formed over here.
But we have angle one, two and three, which are interior angles of this triangle.
And angle four is the exterior angle formed at Vertex Seat already by the exterior angle property.
We know that angle four is equal to angle one plus angle two.
Right, because the exterior angle is equal to the sum of the interior opposite angles.
All right.
Now, angle three plus angle four is equal to 180 degree because these two angles form a linear pair.
Right.
All right.
Now let's substitute the value of angle for which we have over here into this equation.
Therefore, we get angle three plus angle two plus angle one.
That is the sum of the interior angles is equal to 180 degrees.
And remember, this is true for any triangle.