Brett Solberg - Alta High ‘11 Geometry 1.3 - 1.4 Brett Solberg - Alta High ‘11

Warm-up What are the next 2 numbers in the series? 1, 4, 9, 16, 25, 36, , , 5, 10, 9, 18, 17, 34, , , Get out your homework, your signed disclosure, and your notes.

Brief History of Geometry Greek geo = earth metria = measure Using math as an aid in real life. Geometry: the study of the properties and relationships between points, lines, angles, curves and shapes.

Babylonian Geometry 7289 BC

Egyptian Geometry 2700 BC – 1500 BC

Chinese Geometry

Greek Geometry 600 BC Learned from the Egyptians Educational rather than practical Connected geometry to divinity “Let no man ignorant of geometry enter here.” Sign above Plato’s Academy

Euclid 300 BC Greece Euclid’s Elements 10 postulate 465 propositions Standard textbook for 2,000 years

Today’s Objectives To understand basic terms and postulates of geometry. To identify segments and rays and identify parallel lines.

Basic Elements of Geometry Point Space Collinear Points Line Plane Coplanar

Point A point is a location. A point has no size.

Collinear Points Points that lie on the same line. Points A and B are collinear.

Line A series of points that extend in opposite directions without end. l Line l

Naming a line There are many ways to identify this line. l

Plane A flat surface containing many lines and points which extends in the direction of its lines without end. P Plane P Plane ABC Plane BCA

Coplanar Points and lines which lie on the same plane. Line l and points p and r are all coplanar. r l p

Example 1

Example 2

Postulate An accepted statement or fact. Rules of the game.

Postulate 1.1 Postulate 1.2 Postulate 1.3 Postulate 1.4

Quick Break http://www.youtube.com/watch?v=dTAAsCNK7RA&ob=av2e Fun with treadmills

Segment Part of a line consisting of 2 endpoints and all the points between them. What is the difference between PQ PQ

Ray Part of a line consisting of one endpoint and the points on one side of the endpoint. EF Why is it called a sun ray?

Opposite Rays Two collinear rays with the same end point. Opposite rays form a line.

Skew Lines Non-coplanar lines, lines that do not intersect.

Parallel Lines Coplanar lines that do not intersect. AB || CD What other examples of parallel lines in the real world can you think of?

Parallel Planes Planes that do not intersect.

Example 1

Example 2

Homework Time 1.3 1.4 worksheets Use the rest of class to complete the worksheets. I will come around to answer questions.