- A120
- B54
- C60
- D66
Step-by-Step Solution
For parallel lines the co-interior angles sum to 180°, so the other angle = 180 - 120 = 60°.
Answer: C) 60
If one interior angle on a side of a transversal is 120° and the lines are parallel, the other co-interior angle (on the same side) must be:
Class 9The Fifth PostulateGeometry — Foundations
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