In a circle, a chord, 52 cm long, makes a right angle at

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In a circle, a chord, 52 cm long, makes a right angle at the centre. Then the length of the radius of the circle will be

On the basis of question we draw a figure of a circle with centre O ,

OA = OB = radius
∴ ∠OAB = ∠OBA = 45°
OC ⊥ AB

∴ AC = CB =	5√2	cm.
	2

∴ cos OAC =	AC
	OA

⇒ OA cos 45° =	5√2
	2

⇒	OA	=	5√2
	√2		2

⇒ OA =	5√2 × √2	= 5 cm.
	2