Apps. and Interpretation for IBDP Maths Ebook 1 | Page 176

Your Practice Set – Applications and Interpretation for IBDP Mathematics
47
Paper 2 – Problems in Circles and Sectors
Example
Consider a circle with centre O and radius 12 cm. Triangle ABC is drawn such that its
vertices are on the circumference of the circle.
AB � 16.8 cm , BC � 21.5 cm and BAC ˆ � 64
(a) Find the size of the angle ˆ ACB.
(b) (i) Find the size of the angle ˆ ABC .
(ii) Hence, find the length of AC .
(c) (i) Find the size of the angle ˆ AOC .
(ii) Hence, find the length of arc ABC .
[3]
[5]
[6]
Solution
(a)
sin ACB ˆ sin 64
�
16.8 21.5
(M1)(A1) for substitution
sin ACB ˆ � 0.702313487
ACB ˆ � 44.61291137
ACB ˆ � 44.6
A1 N3
[3]
166
SE Production Limited