2) An arc has degree measurement of 270° and arc length of 1870 m. What is the radius of this
circle?

Step-by-step explanation:

The TOTAL circumference of the circle is  pi * d

this is a fraction of the total    270/360

270/360  *   pi * d = 1870 m     solve for 'd'  this is two times the radius

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."