C-15 Vertical Angles Conjecture
If two angles are a pair of vertical angles,
then the angles are congruent.
C-16a Linear Pair Conjecture
If two angles are a linear pair of angles,
then the angles are supplemental.
C-16b Congruent Supplemental Angles Conjecture
If two angles are both congruent and supplemental,
then the angles are right angles.
C-17 Parallel Lines Conjecture
If parallel lines are cut by a transversal,
then corresponding angles, alternate interior angles, and alternate exterior angles are congruent.
C-18 Parallel Line Converse Conjecture
If two lines are cut by a transversal such that corresponding angles, alternate interior angles, and alternate exterior angles are congruent,
then the lines are parallel.
C-19 Midpoint Conjecture
If (x1, y1) and (x2, y2) are the coordinates of the endpoints of a segment, then...
[(x1 + x2)/2, (y1 + y2)/2] are the coordinates of the midpoint of the segment.
C-20 Slope Conjecture
If the coordinates of one point are (x1, y1) and the coordinates of another point are (x2 , y2) then...
the slope of the line through the points can be found using m = (y2 - y1)/(x2 - x1).
C-21 Parallel Slope Conjecture
Two distinct lines in a coordinate plane are parallel iff
their slopes are equal.
C-22 Perpendicular Slope Conjecture
Two distinct lines in a coordinate plane are perpendicular iff
their slopes are negative reciprocals.
C-23 Linear Equation Conjecture
If the graph of a line has a slope of m and a y-intercept of (0 , b), then...
the equation of the line can be written in the form
y = mx + b PT-SLOPE y = m(x - x1) + y1
C-24 Centroid Coordinate Conjecture
If triangle TRY has the coordinates T(a , d), R(b , e) and Y(c , f) then
the centroid of TRY has the coordinates [(a + b + c)/3 , (d + e + f)/3].