Educational worksheet for identifying parts of a circle, including terms like radius, diameter, and circumference.
A worksheet titled "Parts of a Circle Sheet 3" with questions about circle terminology and a diagram of a circle with labeled parts to be identified.
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Step-by-step solution for: Parts of a Circle Worksheet
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Show Answer Key & Explanations
Step-by-step solution for: Parts of a Circle Worksheet
Here's the complete solution to Parts of a Circle Sheet 3, with clear explanations for each answer.
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## ✔ PART 1: Matching Descriptions to Terms
Word Bank:
- Tangent
- Chord
- Radius
- Secant
- Diameter
- Sector
- Circumference
- Segment
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✔ Circumference
> *Explanation:* The circumference is the perimeter (or total length around) the circle. It’s like measuring the “edge” of the circle.
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✔ Segment
> *Explanation:* A segment is the region bounded by a chord and the arc it subtends. Think of it as a “slice” cut off by a straight line (chord), not including the center.
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✔ Radius
> *Explanation:* The radius connects the center point to any point on the circle’s edge. All radii in a circle are equal in length.
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✔ Tangent
> *Explanation:* A tangent line touches the circle at exactly one point and does not cross into it. It’s “just touching.”
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✔ Chord
> *Explanation:* A chord is any straight line segment whose endpoints lie on the circle. It doesn’t have to go through the center.
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✔ Diameter
> *Explanation:* The diameter is a special chord that passes through the center — it’s the longest possible chord and equals twice the radius.
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✔ Secant
> *Explanation:* A secant is a line that intersects the circle at two distinct points. It extends beyond the circle on both sides.
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✔ Sector
> *Explanation:* A sector is like a “pizza slice” — bounded by two radii and the arc between them. Think of it as part of the circle’s area defined by an angle at the center.
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## ✔ PART 2: Labeling the Diagram
We’ll match letters (a–h) to the correct parts using the definitions above.
Looking at the diagram:
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> *Explanation:* This is clearly a line from the center to the circumference — classic definition of radius.
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> *Explanation:* Goes from one side to the other, through the center — that’s the diameter.
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> *Explanation:* Any straight line between two points on the circle is a chord. Since it doesn’t go through the center, it’s not a diameter.
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> *Explanation:* This is the area enclosed by a chord and the arc — that’s a segment.
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> *Explanation:* The blue line just kisses the circle at one point — that’s a tangent.
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> *Explanation:* Bounded by two radii and an arc — this is a sector.
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> *Note:* This is the same as (f) — likely both are meant to be labeled “sector.” If you need to pick one, (f) is the shape, (g) is labeling the area — so still Sector.
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> *Explanation:* The curved arrow traces the entire outer edge — that’s the circumference.
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## 🟩 Final Answer Key:
1) Circumference
2) Segment
3) Radius
4) Tangent
5) Chord
6) Diameter
7) Secant
8) Sector
a) Radius
b) Diameter
c) Chord
d) Segment
e) Tangent
f) Sector
g) Sector
h) Circumference
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✔ You’ve now mastered the key parts of a circle! Great job! 🎯
---
## ✔ PART 1: Matching Descriptions to Terms
Word Bank:
- Tangent
- Chord
- Radius
- Secant
- Diameter
- Sector
- Circumference
- Segment
---
1) I am the distance all the way round the edge of the circle.
✔ Circumference
> *Explanation:* The circumference is the perimeter (or total length around) the circle. It’s like measuring the “edge” of the circle.
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2) I am the area inside the circle that is enclosed by a chord.
✔ Segment
> *Explanation:* A segment is the region bounded by a chord and the arc it subtends. Think of it as a “slice” cut off by a straight line (chord), not including the center.
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3) I am a straight line from the center of the circle to the edge.
✔ Radius
> *Explanation:* The radius connects the center point to any point on the circle’s edge. All radii in a circle are equal in length.
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4) I am a line outside the circle which touches the circle at one point on the edge.
✔ Tangent
> *Explanation:* A tangent line touches the circle at exactly one point and does not cross into it. It’s “just touching.”
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5) I am a straight line starting at one point on the circle and ending at another point on the circle.
✔ Chord
> *Explanation:* A chord is any straight line segment whose endpoints lie on the circle. It doesn’t have to go through the center.
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6) I am a straight line from one side of a circle to the other going through the center point, splitting the circle in half.
✔ Diameter
> *Explanation:* The diameter is a special chord that passes through the center — it’s the longest possible chord and equals twice the radius.
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7) I am a line outside the circle which passes through two different points of the circle, creating a chord.
✔ Secant
> *Explanation:* A secant is a line that intersects the circle at two distinct points. It extends beyond the circle on both sides.
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8) I am the area of a circle enclosed by two radii.
✔ Sector
> *Explanation:* A sector is like a “pizza slice” — bounded by two radii and the arc between them. Think of it as part of the circle’s area defined by an angle at the center.
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## ✔ PART 2: Labeling the Diagram
We’ll match letters (a–h) to the correct parts using the definitions above.
Looking at the diagram:
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a) Line from center to edge → ✔ Radius
> *Explanation:* This is clearly a line from the center to the circumference — classic definition of radius.
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b) Horizontal line across circle, passing through center → ✔ Diameter
> *Explanation:* Goes from one side to the other, through the center — that’s the diameter.
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c) Line connecting two points on circle, NOT through center → ✔ Chord
> *Explanation:* Any straight line between two points on the circle is a chord. Since it doesn’t go through the center, it’s not a diameter.
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d) Shaded area below chord c → ✔ Segment
> *Explanation:* This is the area enclosed by a chord and the arc — that’s a segment.
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e) Line touching circle at only one point → ✔ Tangent
> *Explanation:* The blue line just kisses the circle at one point — that’s a tangent.
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f) Shaded “pizza slice” area from center → ✔ Sector
> *Explanation:* Bounded by two radii and an arc — this is a sector.
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g) Area labeled inside the sector → ✔ Sector *(already labeled correctly)*
> *Note:* This is the same as (f) — likely both are meant to be labeled “sector.” If you need to pick one, (f) is the shape, (g) is labeling the area — so still Sector.
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h) Arrow going all the way around the circle → ✔ Circumference
> *Explanation:* The curved arrow traces the entire outer edge — that’s the circumference.
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## 🟩 Final Answer Key:
Part 1:
1) Circumference
2) Segment
3) Radius
4) Tangent
5) Chord
6) Diameter
7) Secant
8) Sector
Part 2:
a) Radius
b) Diameter
c) Chord
d) Segment
e) Tangent
f) Sector
g) Sector
h) Circumference
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✔ You’ve now mastered the key parts of a circle! Great job! 🎯
Parent Tip: Review the logic above to help your child master the concept of label circle parts worksheet answers.
