Chapter 15 Flashcards
AIA
if lines parallel, alternate int. angles are congruent
Corresponding Angles
angles congruent
SSIA
same side interior angles are supplementary
Alternate Exterior Angles
are congruent
Polygon sum thm
180(n-2) n = # of sides, find measure of all interior angles of a shape
Isosceles Triangle Thm
If two sides of a triangle congruent, angles opposite to the sides congruent.
Triangle Inequality
Given sides of a triangle, 3rd side < sum of other 2 sides
scalene triangle
all sides diff
side-angle relationship
longest side opposite biggest angle (in scalene triangle)
incenter thm
the incenter of a triangle, which is the point where all three angle bisectors intersect, is equidistant from all three sides of the triangle
circumcenter thm
the three perpendicular bisectors of a triangle meet at a single point, called the circumcenter. The circumcenter is also equidistant from all three vertices of the triangle
parallelogram conditions
- opposite sides are congruent
- opposite angles are congruent
- consecutive angles are supplementary
- diagonals bisect each other
rectangle conditions
- parallelogram
- 1 angle is 90 degrees
- diagonals of a rectangle are congruent
rhombus conditions
- parallelogram
- 1 pair of consecutive sides
- diagonals are perpendicular
- diagonals bisect opposite angles
SSEA
same side ext. angles supplementary
exterior angle of a triangle
equivalent to sum of two opposite sides in triangle
