David made a swing for his niece Sarah using ropes 2.4 m long, so that Sarah swings throuh an arc of length 1.2 m. Determine the angle through which Sarah swings, in both radians and degrees.

2 answers

Have you learned the formula
arc length = r(theta) where theta is in radians ?

then theta = arclength/radius
= 1.2/2.4 radians
= 1/2 radians

we know
pi radians = 180º
1 radian = (180/pi)º
.5 radians = (90/pi)º = appr. 28.65º
28.6