00:01
So if you've been following along with any of these videos, you probably already recognize that the arc length, because they give you the theta in radiance, the formula is just theta times r.
00:13
And the reason for that is because in radians, you want the proportion compared to radiance, so all the way around a unit circles times 2 pi.
00:21
But then when you multiply by the formula for circumference, which is 2 pi r, all this stuff cancels out, which is why the formula for.
00:30
Arc length, which is what you're doing in part a, is simply theta times r.
00:36
Now, the other thing that's important is they tell you not r, but they tell you the diameter is 120.
00:42
Well, then you should know that radius is half the diameter, so it's 60 and we're in centimeters.
00:50
So your answer to part a for the arc length s is equal to theta, which they tell you is 2 .2 times the radius, which is 60.
01:01
So just go to a calculator...