SOLUTION: Can someone please help me out? Each side of an inscribed equilateral triangle measures 18 cm. Find the length of one of the minor arcs. Round to the nearest hundredth. Thank

Algebra ->  Circles -> SOLUTION: Can someone please help me out? Each side of an inscribed equilateral triangle measures 18 cm. Find the length of one of the minor arcs. Round to the nearest hundredth. Thank      Log On


   



Question 871450: Can someone please help me out?
Each side of an inscribed equilateral triangle measures 18 cm. Find the length of one of the minor arcs. Round to the nearest hundredth.
Thanks a lot!!

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Find the radius of the circle.
An equilateral triangle has its center on the perpendicular bisector. The formula is a/sqrt(3)
r = 18/sqrt(3)
= 18sqrt(3) / 3
= 6 sqrt(3)
The inscribed angle by the side is 60 degrees
so the central angle = 120 degrees
length of arc = %28theta%2F360%29+%2A+2%2Api%2Ar
=%28120%2F360%29%2A+2%2A3.14%2A6sqrt%283%29
=21.75 cm