Table of contents
- 0. Review of College Algebra4h 43m
- 1. Measuring Angles39m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
1. Measuring Angles
Radians
Problem 2a
Textbook Question
Textbook QuestionFind the length of the arc on a circle of radius 20 feet intercepted by a 75° central angle. Express arc length in terms of 𝜋. Then round your answer to two decimal places.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Arc Length Formula
The arc length of a circle can be calculated using the formula L = rθ, where L is the arc length, r is the radius, and θ is the central angle in radians. To use this formula, it's essential to convert degrees to radians by multiplying the degree measure by π/180.
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Conversion from Degrees to Radians
To convert an angle from degrees to radians, you multiply the degree measure by π/180. For example, a 75° angle can be converted to radians as 75 × (π/180), which simplifies to (75π/180) or (5π/12). This conversion is crucial for applying the arc length formula correctly.
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Rounding and Expressing in Terms of π
When calculating arc length, it is often required to express the answer in terms of π and then round it to a specified number of decimal places. This involves simplifying the expression to include π and then using a calculator to find a numerical approximation, ensuring the final answer is presented clearly.
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