I NEED HELP NOW PLZ

Given the diagram below, michael writes, "segment ac is congruent to segment ac." which of the following reasons allow him to write this statement?

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

About 29% of the earth’s surface is covered by land. the total surface area of the earth is about 510 million square kilometers. what is the area of the earth’s surface covered by land?