Consider the incomplete paragraph proof. Given: P is a point on the perpendicular bisector, l, of MN.
Prove: PM = PN

Line l is a perpendicular bisector of line segment M N. It intersects line segment M N at point Q. Line l also contains point P.

Because of the unique line postulate, we can draw unique line segment PM. Using the definition of reflection, PM can be reflected over line l. By the definition of reflection, point P is the image of itself and point N is the image of . Because reflections preserve length, PM = PN.

point M
point Q
segment PM
segment QM

Match your vocabulary word to its definition. 1. emigration 2. immigration 3. migration 4. overpopulation 5. sustainable development 6. under population 7. unsustainable development 8. urbanization the movement from one place to another the number of people exceeds the available natural resources in an area leaving one's homeland to settle in a new place the increase in the population of a city the movement of people to a new country the ability to meet current needs without reducing the ability to meet future needs resources being used up at a faster rate than they can be replenished birth rate insufficient to replace the existing population