Question

7

Answer 1

Answer:

11 cm

Step-by-step explanation:

r² = 9² + 6.3²

r² = 120.69

r = 10.9859000542

Rounded

r = 11 cm

Answer 2

Answer:

$\rm 10.9 cm$

Step-by-step explanation:

Given that :-

• A chord of a circle is 18 cm long.
• It is 6.3 cm from the centre of the circle.

And we need to find out the radius of the circle.

$\text{ Theorem :-}$

• Perpendicular from the centre of circle , to the chord , bisects the chord .

Using Pythagoras Theorem :-

$\implies \rm OA^2= AB^2+OB^2\\\\\rm\implies OA^2= (6.3 cm)^3+(9cm)^2\\\\\rm\implies OA^2=120.69 \\\\\implies\boxed{\rm OA = 10.9 cm }$

Hence the radius is 10.9 cm