Question

I can’t find anything to help me with this one

Answer 1

`\begin{gathered} \angle DEC+\angle EDC+\angle ECD=180^0(sum\text{ of interior angles in a triangle)} \\ 45^0+65^0+\angle ECD=180 \\ \angle ECD=180-45-65 \\ \angle ECD=70^0 \end{gathered}`