For this case we have that by definition, the arc length of a circle is given by:
[tex]AL = \frac {x * 2 \pi * r} {360}[/tex]
Where:
x: Represents the angle between AB. According to the figure we have that x = 90 degrees.
[tex]r = 7.9 \ cm[/tex]
So:
[tex]AL = \frac {90 * 2 \pi * 7.9} {360}\\AL = \frac {90 * 2 * 3.14 * 7.9} {360}\\AL = \frac {4465,08} {360}\\AL = 12.403[/tex]
Answer:
[tex]12.4\ cm[/tex]
