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An arc of circle M has length [tex]$32 \pi$[/tex] centimeters and the corresponding central angle has a radian measure of [tex]$\frac{8}{9} \pi$[/tex]. What is the radius of the circle?

The radius of the circle is [tex]$\square$[/tex] centimeters.



Answer :

To solve this problem, we need to use the formula for the arc length of a circle. The length [tex]\( L \)[/tex] of an arc of a circle is given by:

[tex]\[ L = r \theta \][/tex]

where [tex]\( r \)[/tex] is the radius of the circle and [tex]\( \theta \)[/tex] is the measure of the central angle in radians.

We are given the arc length [tex]\( L = 32 \pi \)[/tex] centimeters and the central angle [tex]\( \theta = \frac{8}{9} \pi \)[/tex] radians. We need to find the radius [tex]\( r \)[/tex] of the circle.

Given the formula:

[tex]\[ 32 \pi = r \left(\frac{8}{9} \pi\right) \][/tex]

To solve for [tex]\( r \)[/tex], we can divide both sides of the equation by [tex]\( \frac{8}{9} \pi \)[/tex]:

[tex]\[ r = \frac{32 \pi}{\frac{8}{9} \pi} \][/tex]

When we simplify this,

[tex]\[ r = \frac{32 \pi}{\frac{8 \pi}{9}} \][/tex]

Recall that dividing by a fraction is equivalent to multiplying by its reciprocal, so we get:

[tex]\[ r = 32 \pi \times \frac{9}{8 \pi} \][/tex]

The [tex]\( \pi \)[/tex] terms cancel out:

[tex]\[ r = 32 \times \frac{9}{8} \][/tex]

Now, simplifying the multiplication:

[tex]\[ r = 32 \times \frac{9}{8} = 36 \][/tex]

Therefore, the radius of the circle is [tex]\( \boxed{36} \)[/tex] centimeters.