Question

Find the arc length of a central angle of pi/4 in a circle whose radius is 8 inches

A) pi/32 in
B) 2pi in
C) 360 in
D) 60 in

Answer 1

$arc \ length =\theta*r \ \ \ [\theta= \frac{ \pi }{4}; \ \ r=8] } \\ \\ arc \ length = \frac{ \pi }{4} *8 =2 \pi \ \ in$

Answer 2

The formula of the arc is:

Arc Length = 2πR.(C°/360°), where R is the radius, C°(in degrees) is the central angle of the arc:

We are given:
R = 8 in
Central angle = π/4 ≈ (180°/4) = 45°
Length of the arc= 2π x 8 x (45°/360°) →16π(1/8) :

Length of the arc = 2π in (answer B)