The arc corresponding to a central angle of 38 in a circle of radius 20 feet measures feet

Arc length formula is s = r*theta, where s is the arc length and theta is the angle in radians (not degrees).

Here,  we must convert 38 degrees to radians:

38 deg       pi rad
* = 0.211 pi radians = 0.663 rad
      1          180 deg

Then the arc length is (20 ft)(0.663 rad) = 13.26 ft