Answer
pole, polar axis
Work Step by Step
The origin in rectangular coordinates coincides with pole in polar coordinates. This is because at the origin $(0,0)$, we have the radius $r=\sqrt{x^2+y^2}=\sqrt{0^2+0^2}=0$, which places us at the pole.
The positive x-axis in rectangular coordinates coincides with polar axis in the polar coordinates. This is because along the x-axis, we have $y=0$ and we get the radius $r=\sqrt{x^2+0^2}=x$, which is the polar axis.
