Let's solve each question in
Section A and
Section B step by step, using the angle rules for parallel lines. We'll identify the missing angles and provide a correct reason from the given list.
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🔷 Section A
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1. Angle a:
- Given: 48°
- The two lines are parallel, and the transversal forms a triangle-like shape.
- The angle `a` is
vertically opposite to the 48° angle (they are opposite angles at the intersection).
- So, they are equal.
✔ Angle a: 48°
✔ Reason: It is a vertically opposite angle and therefore equal.
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####
2. Angle b:
- Given: 52°
- The angle `b` is on the same side of the transversal and between the two parallel lines — it’s an
interior angle.
- Since the two lines are parallel, interior angles on the
same side add up to
180°.
So:
> b = 180° – 52° =
128°
✔ Angle b: 128°
✔ Reason: It is an interior angle and therefore adds to 180°.
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####
3. Angle c:
- Given: 65°
- The two lines are parallel, and the angle `c` is on the
same side as 65°, but inside the lines — again, this is a pair of
interior angles.
- So, they add up to 180°.
> c = 180° – 65° =
115°
✔ Angle c: 115°
✔ Reason: It is an interior angle and therefore adds to 180°.
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####
4. Angle d:
- Given: 71°
- This is a
corresponding angle — it's in the same position relative to the transversal and the parallel lines.
- Corresponding angles are
equal when lines are parallel.
✔ Angle d: 71°
✔ Reason: It is a corresponding angle and therefore equal.
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🔷 Section B
####
1. Angle a:
- Given: 108°
- The angle `a` is
on a straight line with the 108° angle, so they form a straight line → sum = 180°
> a = 180° – 108° =
72°
✔ Angle a: 72°
✔ Reason: Angles on a straight line add up to 180°.
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####
2. Angle b:
- Given: 43°
- Angle `b` is
alternate to the 43° angle — it's on the opposite side of the transversal but between the parallel lines.
- Alternate angles are
equal.
✔ Angle b: 43°
✔ Reason: It is an alternate angle and therefore equal.
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####
3. Angle c:
- Given: 114°
- Angle `c` is
corresponding to the 114° angle (same position on the transversal across parallel lines).
- Corresponding angles are equal.
✔ Angle c: 114°
✔ Reason: It is a corresponding angle and therefore equal.
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####
4. Angle d:
- Given: 79°
- Angle `d` is
vertically opposite to the 79° angle (they are opposite angles formed by intersecting lines).
- Vertically opposite angles are
equal.
✔ Angle d: 79°
✔ Reason: It is a vertically opposite angle and therefore equal.
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✔ Final Answers:
####
Section A
| Angle | Value | Reason |
|-------|-------|--------|
| a | 48° | It is a vertically opposite angle and therefore equal. |
| b | 128° | It is an interior angle and therefore adds to 180°. |
| c | 115° | It is an interior angle and therefore adds to 180°. |
| d | 71° | It is a corresponding angle and therefore equal. |
####
Section B
| Angle | Value | Reason |
|-------|-------|--------|
| a | 72° | Angles on a straight line add up to 180°. |
| b | 43° | It is an alternate angle and therefore equal. |
| c | 114° | It is a corresponding angle and therefore equal. |
| d | 79° | It is a vertically opposite angle and therefore equal. |
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Let me know if you'd like a diagram explanation or visual guide!
Parent Tip: Review the logic above to help your child master the concept of angle relationships and parallel lines worksheet.