Determine the measure of
CD
from the diagram below.

Answer:
m(arc CD) = 112°
Step-by-step explanation:
Use the property of intersecting chords and angles between these chords,
m∠CED = [tex]\frac{1}{2}(\text{arc CD}+\text{arc}AB)[/tex]
m∠CED + m∠AED = 180°
80° + m∠CED = 180°
m∠CED = 100°
Now substitute the measure of angle CED and arc AB in the expression,
100° = [tex]\frac{1}{2}(88^{\circ}+\text{arc CD})[/tex]
200° = 88° + m(arc CD)
m(arc CD) = 112°