Carefully record the distance and both angles. For each trial carefully record the distance to the subject as measured using a meter stick and the angle read by each protractor. Make a neat table of your data. Put appropriate uncertainty bars on your points in each direction. Think about what this would mean in terms of your graph.
Astronomers measure the angle of stars in the sky throughout the year.
The satellite Hipparcos measured the parallax of 118,000 stars with a resolution of 0.001 arcseconds. After measuring the distance between the pupils of several science faculty you find that they are on average 6.5 cm apart. In reading about binocular vision, you find that people can determine distances accurately using their binocular vision to about 5 meters.