The document provides formulas and examples for calculating slope and midpoints of lines and determining properties of triangles. It includes the slope formula, definitions for lines with the same or opposite reciprocal slopes, the midpoint formula, an example of finding the other endpoint given one endpoint and the midpoint, and an example of proving a triangle is isosceles and right using its vertex coordinates.

1. The Slope Formula:
Between (­19, ­16) and (­3, 14):
If two lines have the same slope, they must be __________.
If two lines have opposite­sign, reciprocal slopes, they must
be ________________.

2. The Midpoint Formula:
Between (­19, ­16) and (­3, 14):
If one endpoint is (3,9) and the midpoint is (0,5), find the
other endpoint:

3. Example: Prove that the triangle with vertices at A(2, 0)
B(­6, 4) and C(­10, ­4) is an isosceles, right triangle.