Subject :IMO Class : Class 10

In the given figure (not drawn to scale), OABC is a quadrilateral with ABC on horizontal ground and O is vertically above A. M is the mid-point of BC. If ∠BAC = 90°, AB = AC = 16 cm and OA = 12 cm, calculate the length of OB.

A25 cm

B15 cm

C20 cm

D28 cm

I don't understand what we are finding. OC or OB clearly angle OAB is 180 degrees,