In the diagram MN is a chord of a circle KMN centre O and radius 10cm. If o, find, correct to the nearest cm, the length of the chord MN.
Attached Figure / Diagram
A
19cm
B
18cm
C
17cm
D
12cm
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
From the diagram
sin 70o = \(\frac{x}{10}\)
x = 10sin 70o
= 9.3969
Hence, length of chord MN = 2x
= 2 x 9.3969
= 18.7938
= 19cm (nearest cm)
Source: Myschool Past Questions Archive (Record #46226)