Video Transcript
Two squares are congruent. If one has side length 78, what is
the side length of the other?
Here, we are told that there are
two congruent squares. We can recall that congruent
squares, like any congruent polygons, have all pairs of corresponding angles
congruent and all pairs of corresponding sides congruent. Informally, we can think of
congruent polygons as being exactly the same shape and size. So, if we sketched the first square
like this, then the second square would be exactly the same shape and size.
We know anyway that since they are
both squares, the corresponding angle measures will all be 90 degrees. But since the squares are
congruent, then they have exactly the same side length. So no matter which square we choose
to have a side length of 78, or 78 length units, then the second square must have
the same side length. So, we can give the answer that the
side length of the other square is 78. And if we needed to give units,
these would be length units.
