In a circle centred at O, AB is a chord and C is any point on AB such that OC is perpendicular to AB. If the radius of the circle is 10 cm and OC = 6 cm, then the length of the chord is :
Answer & explanation
Correct answer: option 4
We have,
OA = 10 cm
OC = 6 cm
In ΔAOC
OA2 = OC2 + AC2
= 102 = 62 + AC2
= AC2 = 100 - 36
= AC2 = 64
= AC = 8 cm
Now the length the chord = 8 × 2 = 16cm