How do astronomers measure the distance to a nearby star

astronomers can measure a star's position once, and then again 6 months later and calculate the apparent change in position. the star's apparent motion is called stellar parallax. the distance d is measured in parsecs and the parallax angle p is measured in arcseconds.                                                                                              

hope this : p

0.3x0.21x0.08kg=mass 1 sheet

mass 500 = 500xmass 1

volume pile = 0.3x0.2x0.048

density=mass/volume= 500xmass 1/0.3x0.2x0.048

v patient student

answer: a. same unit

explanation: