The measure of the arc m ABC is given by the central angles:
mBC = 360 - (146 + 90) (We have a right angle in the figure).
mBC = 360 - (236)
mBC = 124
The total length of the circle is the circumference:
C = 2*pi * r
If we use for pi = 22/7 (approximation)
Then the arc is given by the fraction that multiplies C:
(2 * pi * r) (mBC+m/360) =
Because 2/360 = 180, we have:
( pi * r) * (124/180)
(22/7) * r * (124/180)
Simplifying the fraction 124/180 by 4 (this is the greatest common divisor), we have:
22/7 * r * 31/45
Then, the measure for the arc is given by (a function of r):
m
22/7 * r * 31/45
For instance, if r = 3, then