Alternate Interior Angles Example:
∠3 and ∠5 are alternate interior angles
∠4 and ∠6 are alternate interior angles
Properties:
They are formed when a transversal intersects 2 lines
They are congruent if the 2 lines are parallel
Alternate interior angles are on opposite sides of the transversal and between the two lines.
Alternate interior angles are not adjacent.
Alternate interior do not overlap.
Alternate interior angles do not share a common vertex
Alternate Interior Angles Proof:
Two-Column Proof
Given: a || b and t with transversal t
Prove: ∠3 and ∠5 are congruent
| Statement | Reason |
|---|---|
| a || b and t with transversal t | Given |
| ∠1 ≅ ∠5 | Corresponding Angle Postulate |
| ∠1 ≅ ∠3 | Vertical Angles are Congruent |
| ∠3 ≅ ∠5 | Transitive Property |
Alternate Interior Angles Video
Final Answer
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