Problem 40
Question
Find an angle between \(0^{\circ}\) and \(360^{\circ}\) that is coterminal with the given angle. $$ 361^{\circ} $$
Step-by-Step Solution
Verified Answer
The coterminal angle is 1°.
1Step 1: Understanding Coterminal Angles
Coterminal angles are angles that share the same initial and terminal sides but differ in magnitude by integer multiples of full rotations (360°). To find a coterminal angle within a specific range, such as between 0° and 360°, you typically add or subtract 360° until the condition is satisfied.
2Step 2: Subtract 360° from the Given Angle
Start by subtracting 360° from 361° to obtain an angle within the specified range:\[361^{\circ} - 360^{\circ} = 1^{\circ}\]
3Step 3: Verify the Coterminal Angle
Check the result to ensure it falls within the required range of 0° to 360°. Since 1° is greater than 0° and less than 360°, it is already within the range.
4Step 4: Conclusion: Identify the Coterminal Angle
The coterminal angle of 361° that falls between 0° and 360° is 1°.
Key Concepts
Angle MeasurementSubtracting Angles360 DegreesAngular Rotations
Angle Measurement
Angles are a way to describe the rotation required to get from one ray (or line) to another. This is usually done in degrees, where a full rotation around a point is 360 degrees.
Understanding angle measurement is crucial in geometry. It helps us visualize the amount of turn or rotation represented by numbers.
Understanding angle measurement is crucial in geometry. It helps us visualize the amount of turn or rotation represented by numbers.
- A smaller angle has a smaller degree measure.
- A larger angle represents more rotation and therefore has a higher degree measure.
Subtracting Angles
Subtracting angles is a method used to adjust angle measurements to find equivalent positions on a circle. When given an angle larger than what you need, you can subtract the extra rotation needed to align it within a desirable range.
This is particularly useful when working with coterminal angles — angles that appear different but occupy the same position in circular motion:
This is particularly useful when working with coterminal angles — angles that appear different but occupy the same position in circular motion:
- Angle subtraction helps to reduce any angle greater than 360 degrees by multiples of 360.
- This process realigns angles to fit within a standard 0 to 360-degree measure, making it easier to understand and work with.
360 Degrees
When dealing with angles, 360 degrees represents a full rotation around a circle. This is the basis for standard angle measurement on a circle.
A circle having 360 degrees allows us to describe any angle as a position or direction relative to a fixed starting point.
A circle having 360 degrees allows us to describe any angle as a position or direction relative to a fixed starting point.
- Every complete loop around a circle equates to 360 degrees.
- This concept is fundamental when calculating coterminal angles, as you repeatedly add or subtract 360 to find equivalents.
Angular Rotations
Angular rotations describe how far one line or ray needs to travel around a point to match another line or direction. These rotations can be in any measurement: degree, radian, or revolution.
In most geometric contexts, especially for students, we use degrees:
In most geometric contexts, especially for students, we use degrees:
- A positive rotation moves counterclockwise, marking an increase in degrees.
- A negative rotation moves clockwise, effectively reducing degrees.
Other exercises in this chapter
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