Pls answer the question on Circles

Thanks.

Asked by birpori | 4th Nov, 2018, 02:34: PM

Expert Answer:

Join OD
OD = OA .....radii
so in triangle AOD
angle ODA = angle OAD = x
so angle COD = 2x......exterior angle
so in triangle COD 
OD perpendicular to DC......tangent radius
angle DCB = 90-2x
 
now join BD
angle DBC is exterior angle of tri ABD
also  angle ADB = 90, angle subtended by diameter
so angle DBC = 90 + x

Answered by Arun | 6th Nov, 2018, 09:56: AM