How do you do subtraction using point values

Can someone me do math because i am having a breakdown rn because i don’t get it

What is the angle measure, or angle of depression, between this bird and the bird watcher?

Ineed asap. 35 points. in order for two polygons to be similar, two conditions must be met. first, all pairs of corresponding sides must be in proportion. second, all corresponding angles must be congruent. prove that angle congruence is not enough, by itself, to establish that two polygons are similar. do this by describing or drawing two polygons that are not similar but whose corresponding angles are all congruent.