Download geometry postulates – a complete list

GEOMETRY THEOREMS – CHAPTER 8
T8.1: The sum of the measures of the interior angles of a convex n-gon is
.
Polygon Interior Angles Theorem (pg 507)
Corollary: The sum of the measures of the interior angles of a quadrilateral is
.
(p 507)
T8.2: The sum of the measures of the exterior angles of a convex polygon, one angle at each
vertex, is
.
Polygon Exterior Angles Theorem (pg 509)
T8.3: If a quadrilateral is a parallelogram, then its opposite sides are
. (pg 515)
T8.4: If a quadrilateral is a parallelogram, then its opposite angles are
. (pg 515)
T8.5: If a quadrilateral is a parallelogram, then its consecutive angles are
.
(pg 516)
T8.6: If a quadrilateral is a parallelogram, then its diagonals
.
(pg 517)
T8.7: If both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a
.
(pg 522)
T8.8: If both pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is
a
.
(pg 522)
T8.9: If one pair of opposite sides of a quadrilateral are congruent and parallel, then the
quadrilateral is a
.
(pg 523)
T8.10: If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a
.
(pg 523)
RHOMBUS Corollary: A quadrilateral is a rhombus if and only if it has four
. (pg 533)
RECTANGLE Corollary: A quadrilateral is a rectangle if and only if it has four
. (pg 533)
SQUARE Corollary: A quadrilateral is a square if and only if it is a
and a
. (pg 533)
T8.11: A parallelogram is a rhombus if and only if its diagonals are
. (pg 535)
T8.12: A parallelogram is a rhombus if and only if each diagonals
a pair of apposite angles. (pg 535)
T8.13: A parallelogram is a rectangle if and only if its diagonals are
. (pg 535)
T8.14: If a trapezoid is isosceles, then both pairs of opposite base angles are
.
(pg 543)
T8.15: If a trapezoid has a pair of congruent base angles, then it is an
trapezoid. (pg 543)
T8.16: A trapezoid is isosceles if and only if its diagonals are
T8.17: The midsegment of a trapezoid is
. (pg 543)
to each base and its length is the
of the lengths of the bases. Midsegment Theorem for Trapezoids (pg 544)
T8.18: If a quadrilateral is a kite, then its diagonals are
. (pg 545)
T8.19: If a quadrilateral is a kite, then exactly one pair of opposite angles are
.
(pg 545)
(Have you proved it? If you prove any theorem, you should put a  by the theorem and keep the proof in your notes.)