Math worksheet focusing on adjacent and vertical angles in two intersecting lines, with exercises and diagrams.
Worksheet on adjacent and vertical angles formed by two intersecting lines, featuring diagrams and questions for identifying and calculating angle relationships.
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Step-by-step solution for: Vertical and Adjacent Angles online exercise for
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Show Answer Key & Explanations
Step-by-step solution for: Vertical and Adjacent Angles online exercise for
Problem Analysis:
The worksheet focuses on understanding adjacent angles and vertical angles formed by two intersecting lines. Let's solve the problems step by step.
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#### Part 1: Adjacent Angles
Adjacent angles are angles that share a common side and a common vertex but do not overlap.
1. Identify adjacent angles:
- From the diagram, we see that angles 1 and 2 are adjacent.
- Other pairs of adjacent angles are:
- ∠2 and ∠3
- ∠3 and ∠4
- ∠4 and ∠1
2. Special property of adjacent angles:
- Adjacent angles formed by two intersecting lines add up to 180° because they form a straight line.
- Therefore:
- ∠1 + ∠2 = 180°
- ∠2 + ∠3 = 180°
- ∠3 + ∠4 = 180°
- ∠4 + ∠1 = 180°
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#### Part 2: Vertical Angles
Vertical angles are angles opposite each other when two lines intersect. They are always congruent (equal in measure).
1. Identify vertical angles:
- From the diagram, ∠1 and ∠3 are vertical angles.
- Another pair of vertical angles is ∠2 and ∠4.
2. Relationship between vertical angles:
- Vertical angles are always equal in measure. For example, ∠1 = ∠3 and ∠2 = ∠4.
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#### Part 3: Classifying Angles
For each figure, determine whether the angles are adjacent, vertical, or neither.
1. Figure 1:
- The angles share a common side and a common vertex.
- Answer: Adjacent
2. Figure 2:
- The angles do not share a common side but are opposite each other.
- Answer: Vertical
3. Figure 3:
- The angles do not share a common side and are not opposite each other.
- Answer: Neither
4. Figure 4:
- The angles share a common vertex but do not share a common side.
- Answer: Neither
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#### Part 4: Solving for Angle Measures
We use the properties of adjacent and vertical angles to find the measures.
1. Figure 5:
- ∠1 and ∠2 are adjacent and form a straight line, so ∠1 + ∠2 = 180°.
- ∠2 and ∠3 are vertical angles, so ∠2 = ∠3.
- Let ∠1 = \( x \). Then ∠2 = 180° - \( x \).
- Since ∠2 = ∠3, ∠3 = 180° - \( x \).
- ∠1 + ∠2 = \( x + (180° - x) = 180° \)
- ∠2 + ∠3 = \( (180° - x) + (180° - x) = 360° - 2x \)
2. Figure 6:
- ∠1 and ∠3 are vertical angles, so ∠1 = ∠3.
- ∠2 and ∠4 are vertical angles, so ∠2 = ∠4.
- ∠1 + ∠2 = 180° (adjacent angles)
- Given ∠1 = 70°, then ∠2 = 180° - 70° = 110°.
- ∠3 = ∠1 = 70°
- ∠4 = ∠2 = 110°
- ∠1 + ∠2 + ∠3 = 70° + 110° + 70° = 250°
3. Figure 7:
- ∠1 and ∠2 are adjacent and form a straight line, so ∠1 + ∠2 = 180°.
- ∠2 and ∠3 are vertical angles, so ∠2 = ∠3.
- Given ∠2 = 125°, then ∠1 = 180° - 125° = 55°.
- ∠3 = ∠2 = 125°
- ∠2 + ∠3 = 125° + 125° = 250°
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#### Part 5: Drawing Supplementary Angles
Supplementary angles add up to 180°. To draw ∠3 vertical to ∠1:
1. Draw ∠1.
2. Draw ∠2 supplementary to ∠1 (so ∠1 + ∠2 = 180°).
3. Draw ∠3 vertical to ∠1 (so ∠3 = ∠1).
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Final Answers:
1. Adjacent angles: ∠2 and ∠3, ∠3 and ∠4, ∠4 and ∠1
2. Special property of adjacent angles: ∠1 + ∠2 = 180°, ∠2 + ∠3 = 180°, ∠3 + ∠4 = 180°, ∠4 + ∠1 = 180°
3. Vertical angles: ∠2 and ∠4
4. Classification of angles:
- Figure 1: Adjacent
- Figure 2: Vertical
- Figure 3: Neither
- Figure 4: Neither
5. Angle measures:
- Figure 5: ∠1 = \( x \), ∠2 = 180° - \( x \), ∠3 = 180° - \( x \)
- Figure 6: ∠1 = 70°, ∠2 = 110°, ∠3 = 70°, ∠4 = 110°, ∠1 + ∠2 + ∠3 = 250°
- Figure 7: ∠1 = 55°, ∠2 = 125°, ∠3 = 125°, ∠2 + ∠3 = 250°
Boxed Final Answer:
\[
\boxed{
\text{Adjacent angles: } \angle2 \text{ and } \angle3, \angle3 \text{ and } \angle4, \angle4 \text{ and } \angle1; \text{ Vertical angles: } \angle2 \text{ and } \angle4
}
\]
Parent Tip: Review the logic above to help your child master the concept of adjacent and vertical angles worksheet.