Which of the following number sentences is an example of the associative property of multiplication? 4 × 5 = 5 × 4
6 × 1 = 6
20 × (10 + 6) = (20 × 10) + (20 × 6)
(12 × 3) × 8 = 12 (3 × 8)

arc length = 6.63311 ft.

step-by-step explanation:

the formula the arc measure is:

arc length s=2πr(c)/360

where:

c   is the central angle of the arc in degrees

r   is the radius of the arc

π   is pi, approximately 3.142

using the above formula we get

s =

thus we find that arc length of an arc for a circle of radius 20 feet and central angle 19 degrees is

6.63311 feet