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What is the arc length and then I need to know the area sector

What is the arc length and then I need to know the area sector-example-1
User Jifeng Zhang
by
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1 Answer

12 votes
12 votes

Answer:

1. 6.28 inches

2. 9.42 square inches

Step-by-step explanation:

From the diagram:

• The central angle subtending arc AB = 120 degrees.

,

• The radius of the circle, r=3 inches.

Part A (Arc Length)


\text{Length of an arc=}(\theta)/(360\degree)*2\pi r

Substituting the central angle and radius, we have:


\begin{gathered} \text{Length of an arc=}(120\degree)/(360\degree)*2*\pi*3 \\ =(1)/(3)*6\pi \\ =2\pi\text{ inches } \\ =6.28\text{ inches (to 2 decimal places)} \end{gathered}

Part B (Area of the Sector)


\text{Area of a }\sec tor\text{=}(\theta)/(360\degree)*\pi r^2

Substituting the central angle and radius, we have:


\begin{gathered} \text{Length of an arc=}(120\degree)/(360\degree)*\pi*3^2 \\ =(1)/(3)*9\pi \\ =3\pi\text{ square inches } \\ =9.42\text{ square inches (to 2 decimal places)} \end{gathered}
User MartinC
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