Warm Up

1. The _________________ plane contains the x-axis and the y-axis.

2. Kira needs to buy a piece of pipe that is 40% longer than the 7-inch piece she already has. What length of pipe does Kira need?

3. Simplify .4. Evaluate for .

Lesson 1: Points, Lines, and PlanesGeometry

Vocabulary for Geometry

Definition: a statement that defines a mathematical object.

Undefined term: mathematical term that is not defined using other mathematical terms.

Points, lines, and planes are undefined terms that are the building blocks for defining other terms

Points and Lines

Point: names a location and has no size Represented by a dot Named with a capital letter

Line: a straight path that has no thickness and extends forever.

There are infinitely many points on a line Named with a lowercase letter or using any two points on the

lineC

A BDx

Collinear and Noncollinear

Collinear points: any set of points that lie on the same line

Noncollinear points: points that do not lie on the same line

C

A BDx

Planes

Plane: a flat surface that has no thickness and extends forever

Named with a capital letter or three noncollinear points that lie in the plane

Coplanar: lines or points that are in the same plane Noncoplanar: no plane contains all the lines or points Intersection: the point or set of points in which two

figures meet Two lines intersect at a point Two planes intersect in a line

Example

Name the line below in two different ways.Name all the points.

Z

X WYm

Example

Use the diagram to answer each question.a. What is the intersection of and ?b. What is the intersection of and plane 𝒲? c. What is the intersection of and plane 𝒲?

𝒲N

M

P

K

J

Example

Can two points be noncollinear?

Example

How many points can a line contain?

How many points can a plane contain?

Example

John used two points to name a plane. What mistake did John make in naming the plane?

Homework

1st and 2nd hour: Lesson 1 #1-30

3rd hour: Lesson 1 #1-30 even