Through the vertex A of ΔABC, a line XY is drawn parallel to BC.
Which of the following is correct?
a+b+c = x+a+y
a+b+c=180∘…(1) [Sum of angles in a triangle]
Also, x+a+y=180∘…(2) [Angles on a straight line]
∴ From (1) and (2),
a + b + c = x + a + y