Geometry Mcdougal (2000) Chapter 5

Front 1

Theorem 5-1:

Back 1

Opposite sides of a parallelogram are congruent.

Front 2

Theorem 5-2:

Back 2

Opposite angles of a parallelogram are congruent.

Front 3

Theorem 5-3:

Back 3

Diagonals of a parallelogram bisect each other.

Front 4

Theorem 5-5:

Back 4

If one pair of opposite sides of a quadrilateral are both congruent and parallel, then the quadrilateral is a parallelogram.

Front 5

Theorem 5-6:

Back 5

If both pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is a parallelogram.

Front 6

Theorem 5-4:

Back 6

If both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram.

Front 7

Theorem 5-7:

Back 7

If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram.

Front 8

Theorem 5-8:

Back 8

If two lines are parallel, then all points on one line are equidistant from the other line.

Front 9

Theorem 5-9:

Back 9

If three parallel lines cut off congruent segments on one transversal, then they cut off congruent segments on every transversal.

Front 10

Theorem 5-10:

Back 10

A line that contains the midpoint of one side of a triangle and is parallel to another side, passes through the midpoint of the third side.

Front 11

Theorem 5-11:

Back 11

The segment that joins the midpoints of two sides of a triangle is
1. Parallel to the third side;
2. Half as long as the third side.

Front 12

Theorem 5-12:

Back 12

The diagonals of a rectangle are congruent.

Front 13

Theorem 5-13:

Back 13

The diagonals of a rhombus are perpendicular.

Front 14

Theorem 5-14:

Back 14

Each diagonal of a rhombus bisects two angles of the rhombus.

Front 15

Theorem 5-15:

Back 15

The midpoint of the hypotenuse of a right triangle is equidistant from the three vertices.

Front 16

Theorem 5-16:

Back 16

If an angle of a parallelogram is a right angle, then the parallelogram is a rectangle.

Front 17

Theorem 5-17:

Back 17

If two consecutive sides of a parallelogram are congruent, then the parallelogram is a rhombus.

Front 18

Theorem 5-18:

Back 18

Base angles of a trapezoid are congruent.

Front 19

Theorem 5-19:

Back 19

The median of a trapezoid:
1. is parallel to the bases;
2. has a length equal to the average of the base lengths.