Subjects geometry

Arc Lengths

Step-by-step solutions with LaTeX - clean, fast, and student-friendly.

Search Solutions

Arc Lengths


1. The problem is to find the length of an arc for each given radius and central angle. 2. The formula for arc length is given by $$L = 2\pi r \cdot \left(\frac{\theta}{360}\right)$$ where $r$ is the radius and $\theta$ is the central angle in degrees. 3. Let's calculate each arc length step-by-step: **1)** $r=15$ m, $\theta=315^\circ$ $$L=2\pi \times 15 \times \frac{315}{360} = 30\pi \times 0.875 = 26.25\pi \approx 82.47\text{ m}$$ **2)** $r=12$ yd, $\theta=45^\circ$ $$L=2\pi \times 12 \times \frac{45}{360} = 24\pi \times 0.125 = 3\pi \approx 9.42\text{ yd}$$ **3)** $r=13$ mi, $\theta=285^\circ$ $$L=2\pi \times 13 \times \frac{285}{360} = 26\pi \times 0.7917 = 20.58\pi \approx 64.64\text{ mi}$$ **4)** $r=4$ ft, $\theta=195^\circ$ $$L=2\pi \times 4 \times \frac{195}{360} = 8\pi \times 0.5417 = 4.33\pi \approx 13.60\text{ ft}$$ **5)** $r=7$ mi, $\theta=120^\circ$ $$L=2\pi \times 7 \times \frac{120}{360} = 14\pi \times 0.3333 = 4.67\pi \approx 14.66\text{ mi}$$ **6)** $r=9$ ft, $\theta=315^\circ$ $$L=2\pi \times 9 \times \frac{315}{360} = 18\pi \times 0.875 = 15.75\pi \approx 49.48\text{ ft}$$ **7)** $r=18$ cm, $\theta=105^\circ$ $$L=2\pi \times 18 \times \frac{105}{360} = 36\pi \times 0.2917 = 10.5\pi \approx 32.99\text{ cm}$$ **8)** $r=16$ ft, $\theta=45^\circ$ $$L=2\pi \times 16 \times \frac{45}{360} = 32\pi \times 0.125 = 4\pi \approx 12.57\text{ ft}$$ Final answers: 1) $82.47$ m 2) $9.42$ yd 3) $64.64$ mi 4) $13.60$ ft 5) $14.66$ mi 6) $49.48$ ft 7) $32.99$ cm 8) $12.57$ ft