Points A,B and C lie on a circle. The length of the chord AB is a constant k. Let angle ACB = a degrees and angle ABC = b degrees.
i) Why is a degrees always constant?
ii) How does the sum of the lengths of the chords AC and BC become (k/sin a)(sin b + sin(a + b))?
iii) When b = 90 - a/2, what is the expression for S?
Could someone please help me (especially with ii)?
Thanx very much