Congruent line segments

[Nico]

Hello all –

If line segment AB is congruent to line segment CD, does it also follow that line segment AB is congruent to line segment DC?

Similarly, if angle ABC is congruent to angle DEF, does it follow that angle ABC is congruent to angle FED?

Thanks!

- Nico

 

[HallsofIvy]

One of Euclid's postulates was "if A is congruent to B and B is congruent to C then A is congruent to C".

 

[Bob Brown MSEE]

Hello all –

If line segment AB is congruent to line segment CD, does it also follow that line segment AB is congruent to line segment DC? Yes

Similarly, if angle ABC is congruent to angle DEF, does it follow that angle ABC is congruent to angle FED? No unless 0 or 180 degrees.

Thanks!

- Nico

Just my best guess,
depends on your teacher's definitions.

Euclid says that translation+rotation to achieve congruence is allowed but if DEF=90 then FED=270 deg for most teachers.
It would be reasonable to say it IS Congruent but NOT equal.

With labels, however, "flipping" would be required!