Using AAS

This video link demonstrates the features of the Angle-Angle-Side Theorem.  Of course, there's an example that follows.

Using SSS

One of the easiest postulates to use is the Side-Side-Side Postulate.  This video link gives us a quick overview of what we learned.

Using SAS

Very similar in concept to the ASA Postulate, here is a video link to the description of the Side-Angle-Side Postulate.  Be sure to understand the difference between SAS and ASA.

Using ASA

Here is a video link to the description of Angle-Side-Angle Postulate along with an example.

Proving Congruent Triangles

The image above sets the beginning stages of this proof.  Try to use our class examples to complete the proof before watching this video.

TI-Nspire

One piece of new technology that we have incorporated into our classroom this year is the TI-Nspire calculator.  While it'd be great if all of us have that handheld, for now, the software that I use can help us understand some concepts.  This was a screen shot of the demostration on exterior angles.

Draw a Diagram

This link is to a video with further explanations on how drawing a diagram can help your problem solving skills.  Check it out!

Classifying Triangles

With the minimum of three sides, triangles are the most basic and important polygons.  Learn the basics and build a strong foundation through classifying triangles.  This skill will help you throughout this and future math classes.  This video serves as a great review.

Exterior Angle-Sum

Here is a link to a good review problem for exterior angles.  You can try it first before watching the video.

Outside the Classroom

Polygons are everywhere.  The one that's most easily recognizable is the octagonal stop sign.  Many gazebos also use octagonal designs.

Heptagon

The seven-sided polygon is rarely studied in geometry.  It's called a heptagon.

Polygon Angle Sum

Try to follow the steps that are provided in the slide to solve the problem.  Then play this video to see if you got the correct answer.  If so, great job!

Another Example in Sports

The traditional soccer ball is another example using pentagon in sports.  What's the other polygon that is used?  By the way, the soccer ball is also a 3-D example of a sphere.  We'll learn more about spheres next semester.

Example in Sports

The baseball homeplate is a great example of using polygons.  What's the name of this polygon?  Find other examples in sports and comment below.

Real Life Example

The U.S. Department of Defense has a headquarters in Virginia called "The Pentagon", it was built in 1943.  Interestingly, it has five floors above ground and two floors below ground.  You may recall that it was attacked on 9/11.  This link is to their official website.  Can you find other pentagonal shapes in everyday life?

Exterior Angles

Try the problem that follows the initial instruction of triangle exterior angles.  This skill will help us solve many interesting problems in the upcoming section.

The Louvre Museum

The Lourve Museum is a destination of many Paris tourists.  Check out its interactive website.  The entrance to the museum is a giant glass pyramid made of many triangles.

Pyramids

Slant faces of pyramids are triangular. We'll learn more about 3-D figures in the spring! Can't you find other triangular objects in everyday life?

Triangle Sum Theorem

The sum of the three angles in any triangle is 180 degrees.  Any triangle!  They always add up to 180.  Can it be any easier?  = )

Check out this video!  Try the problem at the bottom of the slide.  Post your answer for x, y, and z in the comments section below.  Thanks!

From My Dice Collection

A 20-sided die. Icosahedron.  How many vertices does this figure have?