Congruent: have the same length
[tex]\begin{gathered} EF\parallel HG \\ EH\parallel FG \\ \\ EF\cong HG \\ EH\cong FG \end{gathered}[/tex]
EFGH is a parallelogram
When two lines form a angle of 90º, the lines are perpendicular
[tex]\begin{gathered} AB\perp CD \\ CB\cong DB \end{gathered}[/tex]
A traingle with two equal sides and two equal angles is a sisosceles traingle
[tex]\begin{gathered} MO\cong NO \\ \angle NMO\cong\angle ONM \end{gathered}[/tex]
MNO is an isosceles triangle
