Question

Based on the figure, which pair of triangles is congruent by the Side Angle Side Postulate?

Triangle ABD and Triangle ECD

Triangle ABC and Triangle ECD

Triangle ABD and Triangle ADC

Triangle ADC and Triangle ABC

Answer 1

@phi @hoblos

Answer 2

I know its NOT B or D

Answer 3

so you have a 50-50 chance at this one.

It should be obvious you, that for the sides, you use the ones that are marked.

the mystery is how do we know the angle between them is equal for 2 of the triangles.

Answer 4

You might search your memory for:

angles, How to show they are = ?

any ideas come to mind ?

Answer 5

no clue

Answer 6

close your eyes, think back to all the stuff you know about angles.

transversals of parallel lines.... no parallel lines here
congruent triangles.... seems like we are trying to prove that
vertical angles... what are those ?

Answer 7

do you see anything like that in your picture?

Answer 8

A...

Answer 9

exactly.

Answer 10

thank you :)