Download Congruent Triangles

Congruent Triangles
Can given numbers make a triangle? Can
a different triangle be formed with the
same information?
Conditions for Unique
Triangles
ASA
two angles must sum to less than 180º
SSS
AAS
two angles must sum to less than 180º
SAS
two shortest sides are longer than the third side
Any set of data that fits these conditions will result in one unique triangle.
Ambiguous Triangle Case
(aka the ‘bad’ word)
b
a
A
This diagram is deceiving -- side-side-angle
data may result in two different triangles.
SSA
Side a is given but it might be possible to ‘swing’ it to either
of two positions depending on the other given values.
An acute or an obtuse triangle may be possible.