Angles in Parallel Lines

Name: _________________________
Date: _________________________

Key Facts:

  • Corresponding angles are equal (F-shape pattern)
  • Alternate angles are equal (Z-shape pattern)
  • Co-interior angles add up to 180° (C-shape pattern)

Part A: Identify the Angle Relationship

State whether each pair of angles are corresponding, alternate, or co-interior.

1. Angles a and e:
_________________________
2. Angles c and f:
_________________________
3. Angles d and f:
_________________________
4. Angles b and h:
_________________________
5. Angles c and e:
_________________________
(Refer to standard parallel lines diagram with transversal: angles a,b,c,d on top line; e,f,g,h on bottom line)

Part B: Calculate Missing Angles

Two parallel lines are cut by a transversal. Find the value of each missing angle.

6. If angle p = 65°, find the corresponding angle q.
q = _________________________
7. If angle r = 112°, find the alternate angle s.
s = _________________________
8. If angle m = 73°, find the co-interior angle n.
n = _________________________
9. If angle k = 48°, find the corresponding angle, then use it to find the co-interior angle to k.
Co-interior angle = _________________________
10. If angle x = 125°, find the alternate angle y, then find an angle corresponding to y.
Alternate angle y = _________________________
Corresponding to y = _________________________

Part C: Problem Solving

11. Two parallel lines are cut by a transversal. One angle measures 3x + 15° and its corresponding angle measures 5x − 25°. Find the value of x.
x = _________________________
12. Two co-interior angles are in the ratio 2:3. Find the size of each angle.
Smaller angle = _____________ Larger angle = _____________