Question

13. Radius of a circle is 5 cm. The length of a chord of the circle is 8 cm. Find the distance of the chord from the centre. *

2 points

9 cm

13 cm

6 cm

3 cm​

Answer 1

Answer:

3cm

Construction

1. draw a line from centre O to one end of the chord B which is 5cm(radius)
2. draw another line which perpendicularly bisect the chord at A from the centre
3. now AOB becomes a right angled triangle right angled at A
4. AO is the distance of chord from centre

Solving

using Pythagoras theorm:

(OB)^2=(OA)^2+(AB)^2

OA^2=OB^2-AB^2

OA^2=5^2-4^2

OA^2=25-16

OA^2=9

OA=√9

OA=3cm