What is the value of x when the Richter scale rating (R) is 6?

Can someone answer it, and plot it, for 20 points and brainliest answer? p.s. they're the same ! : )

Proving the congruent supplements theorem

Acentral angle measuring 160 degrees intercepts an arc in a circle whose radius is 4. what is the length of the arc the circle formed by this central angle? round the length of the arc to the nearest hundredth of a unit. a) 4.19 units b) 6.28 units c) 12.57 units d) 12.57 square units