Find the slope of the line through each pair of points (5, 18), (15, -17)

How do i do this activity, is appreciated

Asap! i'm not good math and i'm lost.

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