Question

In a circle of radius 10 cm, a chord subtends a right-angle at the centre, then the length of the chord is

• A. $10\sqrt{2}$
• B. 10
• C. 20
• D. $20\sqrt{2}$

Answer 1

The correct option is A

$10\sqrt{2}$

Given, chord AB subtends right angle at centre O.
Using Pythagoras theorem,
we get,
$A{B}^2=A{O}^2+O{B}^2\Rightarrow A{B}^2={10}^2+{10}^2=200\Rightarrow AB=10\sqrt{2}cm$