The lengths of the two sides forming the right angle of a right-angled triangle are 21 cm and 20 cm. What is the radius of the circle circumscribing the triangle?

Solution (By Examveda Team)

$$\eqalign{ & AC = \sqrt {{{21}^2} + {{20}^2}} \cr & = \sqrt {441 + 400} \cr & = \sqrt {841} \cr & = 29 \cr & R = \frac{{AC}}{2} = \frac{{29}}{2} = 14.5{\text{ cm}} \cr} $$