Arcs & Central Angles - Worksheet 8 - 10th Grade

Hard

Identify arcs and apply arc addition postulate (Hard)

27 problems · 20-25 minutes · Skills: circles, arcs, angles

About This Worksheet

This hard-level worksheet contains 27 problems designed for 10th Grade students practicing arcs & central angles. Hard worksheets feature challenging problems including multi-step questions, missing values, and real-world applications to push students further.

Arc measure is the bridge between angle measurement and the geometry of circles. These relationships appear in every subsequent circle topic — inscribed angles, tangent-chord angles, and arc length calculations — making fluency with arcs and central angles essential for circle geometry.

  • Calculate arc measures using central angle measures
  • Apply the Arc Addition Postulate to find arc measures in complex figures
  • Distinguish congruent arcs and chords and apply their relationships
  • Use the perpendicular bisector of a chord to locate the center of a circle
  • Set up equations from congruent arc or chord conditions to find missing values

How to Solve: Worked Example

Example Problem: Find the exact arc length of a 60° arc in a circle of radius 6.
Solution Steps:
  1. Arc length is a fraction of the circumference: (θ/360) × 2πr.
  2. 60/360 = 1/6 of the circle.
  3. Circumference = 2π(6) = 12π.
  4. (1/6) × 12π = 2π.
Answer:
Tip: Arc length is a distance and uses 2πr. Sector area is a region and uses πr².
1
Find the exact arc length for a 120° arc in a circle of radius 20.
2
Find the exact arc length for a 180° arc in a circle of radius 18.
3
Find the exact arc length for a 120° arc in a circle of radius 6.
4
Find the exact arc length for a 90° arc in a circle of radius 18.
5
Find the exact arc length for a 120° arc in a circle of radius 30.
6
Find the exact arc length for a 120° arc in a circle of radius 2.
7
Find the exact arc length for a 15° arc in a circle of radius 36.
8
Find the exact arc length for a 135° arc in a circle of radius 9.
9
Find the exact arc length for a 270° arc in a circle of radius 12.
10
Find the exact arc length for a 135° arc in a circle of radius 8.
11
Find the exact arc length for a 15° arc in a circle of radius 36.
12
Find the exact arc length for a 36° arc in a circle of radius 12.
13
Find the exact arc length for a 135° arc in a circle of radius 5.
14
Find the exact arc length for a 45° arc in a circle of radius 16.
15
Find the exact arc length for a 30° arc in a circle of radius 36.
16
Find the exact arc length for a 150° arc in a circle of radius 24.
17
Find the exact arc length for a 36° arc in a circle of radius 16.
18
Find the exact arc length for a 150° arc in a circle of radius 12.
19
Find the exact arc length for a 180° arc in a circle of radius 18.
20
Find the exact arc length for a 180° arc in a circle of radius 8.
21
Find the exact arc length for a 72° arc in a circle of radius 15.
22
Find the exact arc length for a 135° arc in a circle of radius 6.
23
Find the exact arc length for a 36° arc in a circle of radius 24.
24
Find the exact arc length for a 180° arc in a circle of radius 3.
25
Find the exact arc length for a 120° arc in a circle of radius 12.
26
Find the exact arc length for a 40° arc in a circle of radius 16.
27
Find the exact arc length for a 90° arc in a circle of radius 36.

Answer Key

1. 40π/32. 18π3. 4. 5. 20π6. 4π/37. 8. 27π/49. 18π10. 11. 12. 12π/513. 15π/414. 15. 16. 20π17. 16π/518. 10π19. 18π20. 21. 22. 9π/223. 24π/524. 25. 26. 32π/927. 18π

Frequently Asked Questions

How do I download this arcs & central angles - worksheet 8 worksheet?

Click the "Download PDF / Print" button at the top of the worksheet. You can save it as a PDF or print it directly. The answer key will be on a separate page.

How do I find worksheets at different difficulty levels?

Each subtopic has 10 worksheets: Worksheets 1-3 are Easy, 4-7 are Medium, and 8-10 are Hard. Start with Easy worksheets to build confidence, then progress to harder ones.

What skills does this circles worksheet cover?

This worksheet focuses on circles, arcs, angles. It is designed for 10th Grade students and provides structured practice through varied problem types with a worked example to guide students before they begin.

Can I use this worksheet in my classroom?

Yes. All worksheets on K12Worksheets are free for classroom use. You can print copies for your entire class. With 10 worksheets per subtopic at three difficulty levels, you have plenty of options for differentiated instruction and individualized practice.

How many problems are on this worksheet?

This worksheet contains 27 problems. It typically takes 20-25 minutes to complete. An answer key with all solutions is included so parents and teachers can check work quickly.