An arc is intercepted by a central angle of 3π2 radians on a circle with a radius of 18 centimeters. What is the exact length of the arc? Enter your answer, in terms of π , in the box.

Respuesta :

Answer:

The length of the arc is [tex]27\pi \ cm[/tex]

Step-by-step explanation:

step 1

Find the circumference

we know that

The length of a complete circle is equal to the circumference of the circle

The circumference is equal to

[tex]C=2\pi r[/tex]

we have

[tex]r=18\ cm[/tex]

substitute

[tex]C=2\pi (18)[/tex]

[tex]C=36\pi\ cm[/tex]

step 2

we know that

A central angle of  [tex]2\pi[/tex] radians subtends the circumference of [tex]36\pi\ cm[/tex]

so

by proportion

Find the length of the arc by a central angle of [tex]\frac{3\pi }{2}[/tex] radians

[tex]\frac{36\pi }{2\pi}\frac{cm}{radians}=\frac{x}{(3\pi/2)}\frac{cm}{radians} \\ \\x=18*(3\pi/2)\\ \\x=27\pi \ cm[/tex]