Question

a chord of 12cm long of 8cm is away from the of the circle what is the lenght of the chord which is 6cm away from the centre

Answer 1

The length of the chord is 16 cm

Explanation:

Mathematically, a line from the center of the circle to a chord divides the chord into 2 equal portions

From the first part of the question, we can get the radius of the circle

The radius form the hypotenuse, the two-portions of the chord (12/2 = 6 cm) and the distance from the center to the chord forms the other side of the triangle

Thus, by Pythagoras’ theorem; the square of the hypotenuse equals the sum of the squares of the two other sides

Thus,

r^2 = 8^2 + 6^2

r^2= 64 + 36

r^2 = 100

r = 10 cm

Now, we want to get a chord length which is 6 cm away from the circle center

let the half-portion that forms the right triangle be c

Using Pythagoras’ theorem;

10^2 = 6^2 + c^2

c^2 = 100-36

c^2 = 64

c = 8

The full

length of the chord is 2 * 8 = 16 cm