A chord, 7cm long, is drawn in a circle with radius 3.7cm. Calculate the distance of the chord from the centre of the circle
A
0.7cm
B
1.2cm
C
2.0cm
D
2.5cm
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
let the chord be AB = 7cm
radius OA = 3.7cm distance of the = OM using Pythagoras theorem
OA2 = AM2 + OM2
3.72 = 3.52 + OM2
13.69 = 12.25 + OM2
13.69 - 12.25 = OM2
1.44 = OM2
OM = \(\sqrt{1.44}\)
OM = 1.2cm
distance of chord = 1.2cm
Source: Myschool Past Questions Archive (Record #36960)