Geometry Notes Part 1

Unit 1

100

Names a location

Points

200

What does it mean if a line is bisected?

The line is divided into two congruent parts.

300

What is the midpoint formula?

M = (x₁+x₂/2, y₁+y₂/2)

400

What is the transitive property? 

If AB is congruent to BC and BC is congruent to DE, then AB is congruent to DE.

Unit 2

100

What are parallel lines?

A pair of lines that never touch.

200

What are perpendicular lines?

Lines that intersect at 90^o angles.

300

What is the parallel postulate?

For point x, not on like z, there is exactly one line parallel to z through point x.

400

What is the perpendicular bisector theorem?

In a plane, if a point is on the perpendicular bisector of a segment, then it is equidistant from the end points of the segment.

Unit 3

100

Divides a plane figure into two reflected halves with the same size and shape

Line of symmetry

200

What is a reflection?

A mirror image of a shape across a particular line.

300

What are the 4 rotation degrees?

90^o, 180^o, 270^o, 360^o

400

What happens to coordinates if they are reflected across the -x axis?

(y, x)

Unit 4

100

What does SAS stand for?

Side-Angle-Side

200

What does CPCFC stand for?

Congruent Parts of Congruent Figures are Congruent

300

Is SSA a triangle congruence theorem?

No

400

What is required for a triangle to have for the HL theorem to be valid to use?

A 90^o angle

Unit 5

100

What is a rectangle?

A shape with 4 right angles and 2 pairs of Congruent sides.

200

What is a trapezoid?

A quadrilateral with at least one pair of Congruent sides.

300

What theorem says that if a shape is a rectangle, the diagonal lines are always congruent?

Diagonals of a Rectangle Theorem

400

If the only known thing about a shape is that it has congruent diagonals is it always a rectangle?

No, the shape could also have perpendicular diagonals, so it could be a square.