00:01
All right, here we can show whether dominic is correct or not by using the formula that finds the length of an arc.
00:11
And that formula is s equals r times theta, where s is the length, r is your radius, and theta is your angle in radiance.
00:24
So in our first circle, we have angle a, we have a radius of four, and we have a length.
00:31
Of pi.
00:33
So if we substitute those values in, pi is the length, four is the radius, and a is the angle.
00:42
If we solve that for a, we divide by four on both sides, that is pi over four equals a.
00:55
If we look at circle two, we have angle b, the radius is 6 .5, and our length is 13 pi over 8.
01:08
So if we substitute in the same way, 13 pi over 8 is the length equals the radius is 6 .5.
01:21
And then b is the angle.
01:25
And we want to solve this for b in the same way that we solved for circle 1 for a...