00:01
Okay, this is problem 27, and we need to find the radius of the circle o.
00:08
We're going to find the radius of circle o.
00:19
Okay, we know that pt is a tangent, so pt squared is going to be equal to, we're going to extend this down so that we can have a secant.
00:36
That's going to be q.
00:38
It'll be pq.
00:40
So we know that the product of pq times p j will equal the tangent squared.
00:57
So we know that 12 squared is going to equal pq times 8 because pj is 8.
01:12
So this is 144 equals 8 pq.
01:18
Divide by the 8, and we're going to find out that pq is going to equal to 18.
01:40
Okay, so that being said, we know that pq equals pj plus jn plus nq.
02:07
We have 18 here.
02:11
We have eight for the pj...