What is the length of the arc shown in​ red?

45 degrees45°

14 cm

1 answer

To find the length of the arc in a circle, you can use the formula:

\[ \text{Arc Length} = \frac{\theta}{360^\circ} \times 2\pi r \]

where:

  • \(\theta\) is the central angle in degrees,
  • \(r\) is the radius of the circle.

In your case, the central angle \(\theta\) is \(45^\circ\), and the radius \(r\) is given as \(14 , \text{cm}\).

Now, plug in the values:

\[ \text{Arc Length} = \frac{45}{360} \times 2\pi \times 14 \]

First, simplify \(\frac{45}{360}\):

\[ \frac{45}{360} = \frac{1}{8} \]

Now, calculate the arc length:

\[ \text{Arc Length} = \frac{1}{8} \times 2\pi \times 14 \]

\[ = \frac{1}{8} \times 28\pi \]

\[ = \frac{28\pi}{8} = \frac{7\pi}{2} \]

Now, you can calculate this value approximately by using \(\pi \approx 3.14\):

\[ \text{Arc Length} \approx \frac{7 \times 3.14}{2} \approx \frac{21.98}{2} \approx 10.99 , \text{cm} \]

Thus, the length of the arc is approximately \(10.99 , \text{cm}\). If you want the exact answer in terms of \(\pi\):

\[ \text{Arc Length} = \frac{7\pi}{2} , \text{cm} \]