Questions: A circular arc of length 16 feet subtends a central angle of 75 degrees. Find the radius of the circle in feet. (Note: You can enter pi as 'pi' in your answer.)
Transcript text: A circular arc of length 16 feet subtends a central angle of 75 degrees. Find the radius of the circle in feet. (Note: You can enter $\pi$ as 'pi' in your answer.)
Solution
Solution Steps
To find the radius of the circle given the arc length and the central angle, we can use the formula for the arc length of a circle: \( L = r \theta \), where \( L \) is the arc length, \( r \) is the radius, and \( \theta \) is the central angle in radians. First, convert the angle from degrees to radians, then rearrange the formula to solve for the radius \( r \).
Step 1: Convert Central Angle to Radians
The central angle \( \theta \) is given in degrees as \( 75^\circ \). To use it in the arc length formula, we convert it to radians using the conversion factor \( \frac{\pi}{180} \):
\[
\theta = 75 \times \frac{\pi}{180} = 1.3089969389957472 \text{ radians}
\]
Step 2: Use the Arc Length Formula
The formula for the arc length \( L \) of a circle is given by:
\[
L = r \theta
\]
where \( L \) is the arc length, \( r \) is the radius, and \( \theta \) is the central angle in radians. We can rearrange this formula to solve for the radius \( r \):
\[
r = \frac{L}{\theta}
\]
Step 3: Calculate the Radius
Substituting the known values into the formula:
\[
r = \frac{16}{1.3089969389957472} \approx 12.2231
\]
Final Answer
The radius of the circle is approximately \( \boxed{12.22} \) feet.