WAEC - Mathematics (2014 - No. 17)
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
0.7cm
1.2cm
2.0cm
2.5cm
Penjelasan
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
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