Question

find the distance of a chord
8 cm long from the centre of circle of radius 5 cm

Answer 1

answer is 3cm (using pythagoras theorem)

Answer 2

Distance of cord from centre of circle is 3 (cm).

Step-by-step explanation:

1. Given data

  Radius of circle(R) = 5 (cm)

  Length of cord (L) = 8 (cm)

  Let distance of cord from centre of circle= P (cm)

2. We know that shortest distance of cord from centre of circle is perpendicular to cord from centre of circle. Which bisect the cord.

3. Distance of cord from centre of circle is calculated by equation given below

   $P=\sqrt{\left [ R^{2}-\left ( \frac{L}{2} \right )^{2} \right ]}$  ...1)

4. From equation 1)

  $P=\sqrt{\left [ R^{2}-\left ( \frac{L}{2} \right )^{2} \right ]}$

  $P=\sqrt{\left [ 5^{2}-\left ( \frac{8}{2} \right )^{2} \right ]}$

  $P=\sqrt{5^{2}-4^{2}}$

 P = 3 (cm)