Video Transcript
Are two triangles congruent if both
triangles have the same side lengths?
Let’s start by reminding ourselves
that congruent means the same shape and size. All the corresponding pairs of
sides in these triangles would be the same length, and all the corresponding pairs
of angles would be the same size. Sometimes, when we’re answering a
question like this, it can be helpful to draw out a few triangles to
investigate.
Let’s draw out this triangle which
has lengths of four, five, and six units. We could draw another triangle that
also has the same lengths of four, five, and six. We could even draw another one that
looks like this. So, even though these triangles are
all in different orientations, are they still congruent? And the answer is yes. We couldn’t draw a differently
shaped triangle that has these side lengths of four, five, and six.
We can also apply the congruency
rule SSS. This stands for three pairs of
corresponding sides congruent. So, we can see that we have got a
set of sides here in these three triangles which are all of length four. We have another corresponding set
of lengths five units and a third set of corresponding length of six units.
In this example, we use the lengths
of four, five, and six units. But this works for any size of
triangles. If we can show that there are three
pairs of corresponding side lengths or that the triangles in other words here have
the same side lengths, then we would say that these are congruent. And so, our answer to the question
would be yes.
