Guys please help me with this question

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq