Cut or have a hardware store cut the plastic pipes for you. Lay out all your materials on a hard floor.
Lay the 4-foot long piece of pipe on the ground. Place a curved joint on each end of the pipe. Turn the curve downward, so the open end faces down toward the ground when you hold the 4-foot long pipe up.
Stick a 38-inch long piece of pipe into the open ends of the curved joint. Press in firmly so the pipes are tight and secure.
Attach a "T" joint to the end of each pole. Stick the straight center section of the "T' joint onto the poles.
Place one 18-inch pipe section into the "T" joint. Repeat on the opposite side and then opposite barre leg, so you use all four sections and create a base for the barre to balance itself.
Place rubber caps over the ends of the poles on the floor (the supports).