What is the measure of arc RC?
30°
60°
90°
120°

The lines are of the same length and the angles are of the same measure. If you divide the angles by the 360° degree circle, 1/3 of the circle is= 120°
the measure of are RC is 120 degrees.
The know the measure of arc RC, we need to know the type of the angle.
Types of triangle-
In the given problem all the sides of the triangle is equal. Thus it is an equilateral triangle. Thus all the sides of the triangle should be equal.
Hence,
[tex]AC=CR=AR[/tex]
[tex]\angle ACR=\angle ARC=\angle CAR[/tex]
As all the sides are equal and angle are equal in length, thus each section has equal arc measure.
For a circle the sum of all the sides are equal to 360 degrees thus arc of RC is,
[tex]RC=\dfrac{360}{3} \\RC=120[/tex]
Hence the measure of are RC is 120 degrees.
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