In the figure, O is the circumcentre of the triangle ABC, AB = AC and the line OD is perpendicular to the side BC. If BC = 24 cm and OD = 5 cm, then find the circumradius.
13 cm
Given AB = AC, OD ⊥ BC, BC = 24 cm and OD = 5 cm
We know that that perpendicular from the centre bisects the chord. Also given BC = 24 cm.
So, BD = 12 cm
Join AB.
Now, (OB)2=(BD)2+(OD)2=122+52=144+25=169
∴OB=circumradius=13 cm