Answer:
Same-side Interior Angles theorem justifies ∠ 11 + ∠ 10 =180°
Step-by-step explanation:
To Prove:
∠ 11 + ∠ 10 =180°
Proof:
Consider lines are Parallel,then
Corresponding Angles are Equal
∴ ∠ 10 = ∠ 12 say (equation 1)
Now by Linear Pair postulate we have,
∴ ∠ 11 + ∠ 12 = 180° say (equation 2)
Now by replacing ∠12 by ∠ 10 from equation 1 in equation 2 we get
∴ ∠ 11 + ∠ 10 = 180°
Hence proved the above statement.
