00:01
Here i've drawn the initial ray.
00:04
So angle a has a measure of 0 .7 radians.
00:15
Okay so this is the terminal ray for angle a.
00:24
And we have a circle of radius 6 that is centered at the vertex of a.
00:33
So we have r is equal to 6.
00:41
Okay this is also r.
00:45
And we want to know this distance of the arc subtended by angle a.
00:51
So we have the angle a is 0 .7 radians.
00:56
The number of radians for the entire circle is 2 pi.
01:02
And this ratio is going to be equal to the length of the arc.
01:08
So this is l.
01:09
Divided by the circumference of the circle which is 2 pi r.
01:16
So that's 12 pi since r is 6.
01:22
So then i'll multiply by 12 pi on both sides.
01:24
So i get l is equal to 6 times 0 .7 where r is equal to 6.
01:35
So we see that the length of the arc is equal to 0 .7 times the radius of the circle.
01:44
So we have 0 .7 there.
01:45
And then when we actually calculate the length we get 4 .2 centimeters.
01:54
Next we'll look at angle b.
01:57
Angle b is 4 .5 radians.
02:04
Okay so this is angle b.
02:14
And we have a circle that is centered at b's vertex.
02:21
And it has a radius of length 2 .4 centimeters...