I need help with these questions.

If chord ab is congruent to chord cd, then what must be true about ef and eg?

Plzzz answer both questions and i will give you 100 points

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