Test it out

cd sqrt
cmake -B build -S . -DCMAKE_INSTALL_PREFIX=~/.local # NOTE: change this to whatever you want, or omit it. if you omit, it will default install to /usr and require sudo
cd build
# NOTE: did you read the above note?
make
# NOTE: are you sure?
make install

Now that package and it's library + headers can be used by our hypot package.

cd hypot
mkdir build
cd build
cmake ..
make

And it should compile & run. Amazing!