The side of an equilateral triangle inscribed in a circle is √3*r. So,
l=√3*r Where l= side of equilateral triangle and r= radius of circle.
Given the side length: l= 12√3. So, plug in l=12√3 in the above formula.
12√3= √3*r
So, r= 3 (Dividing each sides by √3).
So, the radius of the circle is 3 units long.
Formula to find the apothem is:
[tex]a=\frac{\sqrt{3}}{6} l [/tex]
[tex] a=\frac{\sqrt{3}}{6} 12\sqrt{3 [/tex]
[tex] a=\frac{12*3}{6} [/tex] Since√3*√3= 3
[tex] a=\frac{36}{6} [/tex]
a=6
So, apothem is 6 units long.