If in the following figure (not to the scale), $$\angle$$ACB = 135$$^\circ$$ and the radius of the circle is $$2\sqrt{2}$$ cm, then the length of the chord AB is:
In cyclic quadrilateral ACBD,
Sum of opposite angles =Â 180$$^\circ$$
$$=$$> Â $$\angle$$ACB +Â $$\angle$$ADB =Â 180$$^\circ$$
$$=$$> Â 135$$^\circ$$ + $$\angle$$ADB = 180$$^\circ$$
$$=$$> Â $$\angle$$ADB =Â 45$$^\circ$$
Angle subtended by an arc at the centre of the circle is twice the angle subtended by the arc at any point on the circle
$$=$$> Â $$\angle$$AOB =Â 2$$\angle$$ADB
$$=$$> Â $$\angle$$AOB = 2(45$$^\circ$$)
$$=$$> Â $$\angle$$AOB = 90$$^\circ$$
In $$\triangle$$AOB,
OA$$^{2}$$ + OB$$^{2}$$ = AB$$^{2}$$
$$=$$> Â $$\left(2\sqrt{2}\right)^2+\left(2\sqrt{2}\right)^2$$ = AB$$^{2}$$
$$=$$> Â AB$$^{2}$$ = 8 + 8
$$=$$> Â AB$$^{2}$$ = 16
$$=$$> Â AB = 4 cm
$$\therefore\ $$Length of the chord = 4 cm
Hence, the correct answer is Option A
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