AD is a diameter of a circle and AB is a chord. If AD = 10 cm, AB = 8 cm, the distance of AB from the centre of the circle is
Answers
Answer:
the answer is 3cm
Step-by-step explanation:
since diameter is 10 cm
radius is 5cm
also length of chord is 8cm
it is a property that the perpendicular drawn from the centre to the chord bisects the chord ie 1:1 ratio
now we get a right triangle with hypotenuse is 5cm and base is 4cm
applying pytagorus theorem we get height of perpendicular as 3cm which is the distance from the centre to chord.
AD is the diameter of the circle of length is AD = 34 cm
AB is the chord of the circle of length is AB = 30 cm.
Distance of the chord from the centre is OM.
Since the line through the centre to the chord of the circle is the perpendicular bisector, we have
∠OMA = 90° and AM = BM.
∴ ΔAMC is a right triangle.
Apply Pythagorean Theorem
OA2 = AM2 + OM2 --------(1)
Since the diameter AD = 34 cm., radius of the circle is 17 cm.
Thus,
OA = 17 cm
Since AM = BM and AB = 30 cm, we have AM = BM = 15 cm.
Substitute the values in equation (1), we get
OA2 = AM2 + OM2
172 = 152 + OM2
OM2 = 289 – 225
OM2 = 64
OM = 8.
Distance of the chord from the centre is 8 cm.