Which of these is the area of a sector of a circle with r 18 given that its arc length is 6π?

To find the area of a sector, we can use the formula:

Area of sector = (θ/360°) × πr²

where θ is the central angle in degrees and r is the radius of the circle. Here, we know the radius (r) is 18.

First, we need to find the central angle θ. The arc length (L) of a sector can be calculated using:

L = (θ/360°) × 2πr

Given that the arc length is 6π and the radius is 18, we can set up the equation:

6π = (θ/360°) × 2π × 18

Simplifying this, we get:

6 = (θ/360°) × 36

Now, multiply both sides by 360°:

6 × 360° = θ × 36

Next, simplifying further:

2160° = θ × 36

This gives us:

θ = 2160° / 36 = 60°

Now that we have θ, we can substitute it back into the area formula:

Area = (60/360) × π × (18)²

Calculating further:

Area = (1/6) × π × 324 = 54π

Thus, the area of the sector is 54π square units.

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