Question | Answer |
Parallelogram | a quadrilateral with both pairs of opposite sides parallel. |
Rhombus | a parallelogram with four congruent sides. |
Rectangle | a parallelogram with four right angles. |
Square | a parallelogram with four congruent sides and four right angles. |
Kite | a quadrilateral with two pairs of adjacent sides congruent and no opposite sides congruent. |
Trapezoid | a quadrilateral with exactly one pair of parallel sides. |
Isosceles Trapezoid | a trapezoid whose nonparallel opposite sides are congruent. |
Theorem 6.1 | Opposite sides of a parallelogram are congruent. |
Theorem 6.2 | Opposite angles of a parallelogram are congruent. |
Theorem 6.3 | The diagonals of a parallelogram bisect each other. |
Theorem 6.4 | If three (or more) parallel lines cut off congruent segments on one transversal, then they cut off congruent segments on every transversal. |
Theorem 6.5 | If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. |
Theorem 6.6 | If one pair of opposite sides of a quadrilateral is both congruent and parallel, then the quadrilateral is a parallelogram. |
Theorem 6.7 | If both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram. |
Theorem 6.8 | If both pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is a parallelogram. |
Theorem 6.9 | Each diagonal of a rhombus bisects two angles of the rhombus. |
Theorem 6.10 | The diagonals of a rhombus are perpendicular. |
Theorem 6.11 | The diagonals of a rectangle are congruent. |
Theorem 6.12 | If one diagonal of a parallelogram bisects two angles of the parallelogram, then the parallelogram is a rhombus. |
Theorem 6.13 | If the diagonals of a parallelogram are perpendicular, then the parallelogram is a rhombus. |
Theorem 6.14 | If the diagonals of a parallelogram are congruent, then the parallelogram is a rectangle. |
Base angles of a trapezoid | Two angles that share a base of a trapezoid. |
Theorem 6.15 | The base angles of an isosceles trapezoid are congruent. |
Theorem 6.16 | The diagonals of an isosceles trapezoid are congruent. |
Theorem 6.17 | The diagonals of a kite are perpendicular. |
Midsegment of a trapezoid | The segment that joins the midpoints of the nonparallel opposite sides. |
Trapezoid Midsegment Theorem | 1) The midsegment of a trapezoid is parallel to the bases.2) The length of the midsegment of a trapezoid is half the sum of the lengths of the bases. |