Special Angle Pairs Notes - Lindsay Bowden - Free Printable

Let's solve each of the 12 problems on this "Special Angle Pairs Practice" worksheet. The goal is to identify each marked angle pair as:

- Complementary (C): Two angles that add up to 90°
- Supplementary (S): Two angles that add up to 180°
- Vertical (V): Angles opposite each other when two lines cross
- Adjacent (A): Angles that share a vertex and a side but do not overlap
- Linear Pair (LP): Adjacent angles that form a straight line (i.e., supplementary and adjacent)

We’ll go through each one carefully.

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1.

Two angles sharing a common vertex and side, forming a "corner" shape with three rays.

- They are adjacent (share a side and vertex)
- Not vertical (not opposite)
- Not linear pair (don’t form a straight line)
- No degree measures → can't check complementary/supplementary

✔ Answer: A

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2.

Two intersecting lines, with two dots marking angles across from each other.

- These are vertical angles (opposite angles formed by intersecting lines)
- Vertical angles are always equal
- Not adjacent or linear pairs
- Can't determine if they're C or S without measures

✔ Answer: V

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3.

Two angles at the same vertex, sharing a side; one appears to be above the other.

- They are adjacent (share a vertex and side)
- Do they form a straight line? No — not a linear pair
- No measure given → can't tell if C or S

✔ Answer: A

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4.

Two intersecting lines, with two dots marking angles on opposite sides.

- These are vertical angles (opposite each other)
- So, V

✔ Answer: V

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5.

Right angle (90°) split into two angles: one labeled with a dot, another ray going diagonally.

- One angle is part of the right angle, so the two angles together make 90°
- Therefore, they are complementary (C)
- Also, they are adjacent (share a side and vertex)
- Not vertical, not linear pair (since sum ≠ 180°)

✔ Answer: C, A

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6.

Three rays from a point, with two dots marking angles that are opposite each other.

- The two angles are vertical (they are opposite angles formed by intersecting lines)
- So, V

✔ Answer: V

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7.

Two separate angles shown:
- One is 72°, the other 18°
- Together: 72 + 18 = 90°
- So, they are complementary (C)

But are they adjacent? No — they’re not connected or sharing a side.
They don’t appear to be related geometrically.

So only C

✔ Answer: C

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8.

Several rays from a point, two dots marking two angles that share a side and vertex.

- They are adjacent (share a side and vertex)
- Are they a linear pair? No — they don’t form a straight line
- No measures → can't say C or S
- Not vertical

✔ Answer: A

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9.

Two angles sharing a vertex and side, forming a "V" shape, with one ray extending beyond.

- They are adjacent
- Do they form a straight line? Yes — looks like they are next to each other on a straight line
- So, linear pair (LP) → which means they are also supplementary (S)

✔ Answer: A, LP, S

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10.

Two angles sharing a vertex and side, forming a corner with a straight line.

- They are adjacent
- Form a straight line → linear pair (LP)
- So, they are supplementary (S)

✔ Answer: A, LP, S

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11.

Two intersecting lines, with two dots marking angles across from each other.

- These are vertical angles
- So, V

✔ Answer: V

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12.

Two angles shown separately:
- One is 50°, the other 130°
- Sum: 50 + 130 = 180° → supplementary (S)

Are they adjacent? No — not connected
Not vertical (no intersection shown)
No shared side → not adjacent

So only S

✔ Answer: S

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✔ Final Answers:

| # | Answer |
|---|--------|
| 1 | A |
| 2 | V |
| 3 | A |
| 4 | V |
| 5 | C, A |
| 6 | V |
| 7 | C |
| 8 | A |
| 9 | A, LP, S |
| 10 | A, LP, S |
| 11 | V |
| 12 | S |

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🔍 Summary of Concepts Used:

- Complementary (C): Add to 90°
- Supplementary (S): Add to 180°
- Vertical (V): Opposite angles from intersecting lines
- Adjacent (A): Share a side and vertex
- Linear Pair (LP): Adjacent angles that form a straight line (always supplementary)

Let me know if you'd like this in printable format or with diagrams!