Question

The radius of a circle is 6 cm. The perpendicular distance from the centre of the circle to the chord which is 8 cm in length is–

• A. √5 cm
• B. 2√5 cm
• C. 2√7 cm
• D. √7 cm

Answer 1

The correct option is B

2√5 cm

In figure

AL = $\frac{AB}{2}$ = 4 cm; OA = 6 cm

$\therefore$ ${OL}^2$ = ${OA}^2$ - ${AL}^2$ = ($6^2$ - $4^2$) = 20

Or, OL = $\sqrt{20}$ = 2 $\sqrt{5}$ cm