In the diagram above MN is a chord of a circle KMN centre O and radius 10cm. If < MON = 140^\circ, find, to the nearest cm, the length of the chord MN.
A
10cm
B
19cm
C
17cm
D
12cm
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Find the diagram
Sin 70^\circ
x = 10 Sin 70^\circ
= 9.3969
Hence, length of chord MN = 2x
= 2 \times 9.3969
= 18.79
= 19cm (nearest cm)
Source: Myschool Past Questions Archive (Record #46357)