00:01
The first part of the question, we're given a line drawn from the center of a circle perpendicular to a chord.
00:06
So for example, this xy is a chord, and a line drawn from the center of a circle perpendicular to the chord will actually bisect the chord.
00:19
That is, xt length is the same as ty length.
00:25
Now we are given this circle, oc is the radius, we are given is r.
00:33
So we are drawing x and o, this is also the radius r.
00:39
And we are drawing o and y, this is also the radius r.
00:44
Now we are given that xy is 3 over 2r because xt length is the same as ty.
00:55
So ty over here will be half of this length and so ty will be 3 quarter r.
01:04
Now i want to prove that ct is 4 plus root 7 over 4r.
01:09
Now ct is the oc plus ot.
01:19
Oc is r.
01:22
Now ot by pythagoras theorem, we have a right angle triangle here...