A,B and C are three points on the circle. If AB = AC = $$7 \sqrt 2$$ cm and $$\angle$$BAC = 90$$^\circ$$, then the radius is equal to:

Given A,B and C are three points on the circle.

$$\angle$$BAC = 90$$^\circ$$

Angle subtended by the diameter at any point on the circle is 90$$^\circ$$ and the inverse is also true.

So BC is the diameter subtending 90$$^\circ$$ at point A as shown in figure.

AB = AC = $$7 \sqrt 2$$ cm

Let the radius of the circle = r

From the figure,

r$$^2$$ + r$$^2$$ = ($$7 \sqrt 2$$)$$^2$$

$$\Rightarrow$$  2r$$^2$$ = 49 x 2

$$\Rightarrow$$  r$$^2$$ = 49

$$\Rightarrow$$  r = 7 cm

$$\therefore\ $$Radius of the circle = 7 cm

Hence, the correct answer is Option B