Answer:
Explanation:
Concepts used :
sum of angles at a point on straight line is 180
if a transversal intersects two parallel lines then alternate angles are equal.
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∠∠∠∠∠
m∠1 + m∠2 + m∠3 = 180 ____________(A)
reason :sum of angles at a point on straight line is 180
these angles lie on LAM at point A
m∠1 = m∠5
Reason: alternate angles y ∥ x and AC is transversal
m∠3 = m∠6
Reason: alternate angles y ∥ x and AB is transversal
Substituting m∠1 with m∠5 and m∠3 with m∠6
in equation A---m∠1 + m∠2 + m∠3 = 180
m∠5 + m∠2 + m∠6 = 180
Hence proved.