Question

The radius of the circle is 25 cm and the length o0f one of its chord is 40cm. find the distance of the chord from the centre.

Answer 1

As perpendicular from centre bisects the chord,

$\Rightarrow CA=AD=20$cm

In $\Delta OAD$, $O{D}^2=O{A}^2+A{D}^2$(Pythagoras thereom)

$\Rightarrow O{A}^2=O{D}^2-A{D}^2$

$={25}^2-{20}^2$

$=625-400=225$

$\Rightarrow OA=15$cm

OA is distance of chord from O.