The radius of a circle is 8 inches. What is the angle of an arc 2π inches long?

π/4 radians

Step-by-step explanation:

The arc length formula is s = rФ, where Ф is the central angle (in radians).

Here, r = 8 inches and s = arc length = 2π inches.  We need to find the central angle, Ф.  The formula given above is s = rФ, or, equivalently,

Ф = s/r.

Here, the central angle is Ф = s/r = 2π/8, or π/4 radians.

x = central angle apc = measure of minor arc ac

the two angles x and 30 add to 180, so x+30 = 180 and x = 180-30 = 150. the measure of minor arc ac is 150 degrees.

what we need to do from here is find the circumference and then multiply it by x/360 since there are 360 degrees in a circle. in this case, x = 150, so x/360 = 150/360 = 15/36 = 5/12. the shortest distance along the curve from a to c is 5/12 of the distance around the entire circle (aka circumference)

c = circumference

c = pi*d

c = pi*24

c = 24pi

now multiply this by 5/12 to get

distance along minor arc ac = (5/12)*(circumference)

distance along minor arc ac = (5/12)*(24pi)

distance along minor arc ac = 10pi

the formula you can use is

l = (x/360)*pi*d

with

l = length of minor arc

x = central angle

d = diameter

which essentially is the steps we took though a bit differently.