We can find the missing angles using the drawing below.
Then,
[tex]\begin{gathered} 360=60+60+55+x+y \\ \text{and} \\ 55+y=x \\ \Rightarrow240=2(55+y) \\ \Rightarrow120=55+y \\ \Rightarrow y=65 \\ \Rightarrow x=120 \end{gathered}[/tex]
Therefore
25)
Arc JML covers an angle equal to 65+55+60=180; thus, ArcJML is a semicircle of R.
27)
