In a circle, AB is a chord. If ∠ACB = 50°, find ∠ADB.
50°
In the given figure, points C and D lie on the same arc of the circle, on the same side of chord AB.
Angles subtended by the same chord at points lying in the same segment of a circle are equal, so \(\angle ADB = \angle ACB\).
Since \(\angle ACB = 50^\circ\), it follows that \(\angle ADB = 50^\circ\).
In same segment, if ∠ACB = 40°, find ∠ADB.

ABCD is a cyclic quadrilateral. If ∠A = 70°, find ∠C.

How many tangents can be drawn to a circle from a point outside it?
There are two concentric circles. The radii of the two circles are 100 m and 110 m respectively. A wheel of radius 30 cm rolls on the smaller circle and another wheel rolls on the larger circle. After they have completed one revolution, it is found that the two wheels rolled equal number of times
on their respective axes. What is the radius of the other wheel ?