In the given figure, AB is the diameter of the circle. If vertBCD = 110 deg and chord CD = chord CB, find the value of t.

The figure shows a cyclic quadrilateral ABCD inscribed in a circle with center O.

• AB is a diameter because it passes through the center O.
• $\angle BCD = 110^\circ$.
• $\angle ADC = t$.
• Chord CD = Chord CB (indicated by the double hash marks).

Since AB is a diameter, the angle subtended by the diameter at any point on the circumference is $90^\circ$.
Therefore, $\angle ADB = 90^\circ$.

In a cyclic quadrilateral, opposite angles sum to $180^\circ$.

Substitute the given value for $\angle BCD$:

Given that chord CD = chord CB.
Equal chords subtend equal angles at the circumference. This means the angles subtended by these chords at any point on the remaining part of the circumference are equal.
Specifically, $\angle CAD$ (subtended by chord CD) is equal to $\angle CAB$ (subtended by chord CB).
So, $\angle CAD = \angle CAB$.
Since $\angle DAB = \angle CAD + \