4th question help plzz with steps

I give

72 degrees

Step-by-step explanation:

A central angle equals the degree of the arc.

If the circumference is 20 and the arc is 4 than means the

arc is 4/20= 1/5 of the circumference.

A circles circumference is also always equal to 360 degrees.

So we need to find out what 1/5 of 360 is to find the degree of the arc.

So then 1/5*360= 72

so the Arc is equal to 72 degrees of the whole circle, which means the central angle is equal to 72  degrees as well.

i think asking google will you get the answer to that question