(i)
The angle 78° is supplementary to the angle BCE. Then we have:
[tex]\begin{gathered} 78\degree+B\hat{C}E=180\degree \\ B\hat{C}E=180\degree-78\degree \\ B\hat{C}E=102\degree \end{gathered}[/tex]
(ii)
When the vertex of a angle formed by two segments is located on the circle, the corresponding arc formed by the two segments is the double of the angle. Then we have:
[tex]\begin{gathered} B\hat{A}E=B\hat{D}E=\frac{arc\text{ BR}}{2} \\ B\hat{A}E=66\degree \\ \therefore B\hat{D}E=66\degree \end{gathered}[/tex]
(iii)
Since BDE is a right triangle, we have:
[tex]\begin{gathered} D\hat{B}E+B\hat{D}E+90\degree=180\degree \\ D\hat{B}E+66\degree+90\degree=180\degree \\ D\hat{B}E=180\degree-90\degree-66\degree \\ D\hat{B}E=24\degree \end{gathered}[/tex]