Understanding the Relationship Between Central Angles and Arc Lengths

Oct 13, 2025 by wbrum.org 118 views

Understanding the Relationship Between Central Angles and Arc Lengths

When dealing with circles, it's essential to understand the relationship between central angles and arc lengths. A central angle is an angle formed by two radii that intersect at the center of a circle. The measure of a central angle is typically expressed in radians or degrees. On the other hand, an arc length is the distance along a circle's circumference between two points on the circle.

The Formula for Arc Length

The formula for arc length is given by:

L = rθ

Where:

L is the arc length
r is the radius of the circle
θ is the central angle in radians

In this problem, we are given a central angle of 6 radians that intersects an arc of length 14 in. We need to find the length of the radius, r, of the circle.

Using the Formula to Find the Radius

We can use the formula for arc length to find the radius of the circle. Plugging in the given values, we get:

14 = r(6)

To find the radius, we need to isolate r. We can do this by dividing both sides of the equation by 6:

r = 14/6

Simplifying the fraction, we get:

r = 7/3

Therefore, the length of the radius, r, of the circle is 7/3 inches.

Comparing the Answer Choices

Let's compare our answer with the given answer choices:

A. r = 6/14 This is incorrect, as it does not match our calculated value.
B. r = 14/6 This is correct, as it matches our calculated value.
C. r = 6 + 14 This is incorrect, as it does not match our calculated value.
D. This option is not provided.

Therefore, the correct answer is **B. r = 14/6.

Conclusion

In this problem, we used the formula for arc length to find the length of the radius of a circle. We were given a central angle of 6 radians that intersects an arc of length 14 in. By plugging in the given values and isolating the radius, we found that the length of the radius is 7/3 inches. This matches answer choice B, which is r = 14/6.
A Circle Has a Central Angle of 6 Radians That Intersects an Arc of Length 14 in: Q&A

Q: What is the relationship between central angles and arc lengths?

A: A central angle is an angle formed by two radii that intersect at the center of a circle. The measure of a central angle is typically expressed in radians or degrees. An arc length is the distance along a circle's circumference between two points on the circle.

Q: What is the formula for arc length?

A: The formula for arc length is given by:

L = rθ

Where:

L is the arc length
r is the radius of the circle
θ is the central angle in radians

Q: How do I use the formula to find the radius of a circle?

A: To find the radius, you need to isolate r. You can do this by dividing both sides of the equation by θ. For example, if you are given an arc length of 14 in and a central angle of 6 radians, you can plug in the values and solve for r.

Q: What if I am given a central angle in degrees instead of radians?

A: If you are given a central angle in degrees, you need to convert it to radians before using the formula. There are 2π radians in 360 degrees, so you can convert degrees to radians by multiplying by (2π/360).

Q: Can I use the formula to find the arc length if I know the radius and central angle?

A: Yes, you can use the formula to find the arc length if you know the radius and central angle. Simply plug in the values and solve for L.

Q: What if I am given an arc length and a central angle, but I don't know the radius?

A: In this case, you can use the formula to find the radius. Simply plug in the values and solve for r.

Q: Are there any other formulas I should know for circles?

A: Yes, there are several other formulas you should know for circles. These include:

C = 2πr (the formula for the circumference of a circle)
A = πr^2 (the formula for the area of a circle)
θ = L/r (the formula for the central angle in radians)

Q: How do I apply these formulas in real-world situations?

A: These formulas can be applied in a variety of real-world situations, such as:

Calculating the circumference of a wheel or tire
Finding the area of a circular table or room
Determining the central angle of a sector of a circle
Calculating the arc length of a circular path or road

Conclusion

In this Q&A article, we have covered the relationship between central angles and arc lengths, the formula for arc length, and how to use the formula to find the radius of a circle. We have also discussed how to apply these formulas in real-world situations. Whether you are a student or a professional, understanding these formulas is essential for working with circles and solving problems involving arc lengths and central angles.