Question

A circle has a radius of 12.6 cm.

What is the exact length of an arc formed by a central angle measuring 120°?



Enter your answer in the box. Express your answer using π .

Answer 1

8.4 cm is the answer

Explanation:

k12 verified (I took the test)

Answer 2

we know that

[the length of a circumference]=2*pi*r
for r=12.6 cm
[the length of a circumference]=2*pi*(12.6)---------> 25.2*pi cm
this is the length for an arc of 360° (full circumference)

now calculate the length for an arc of 120° (applying a rule of three)
if 360°-----------------> 25.2*pi cm
120°---------------> X
X=120*25.2*pi/360----------> 8.4*pi

the answer is 8.4*pi