Using HL

When you have a right triangle, consider the Hypotenuse-Leg Theorem.  This video link gives a good example for the last postulate/theorem that we use to prove triangles congruent.  The example shows another way to do proofs - by using flow-chart style proofs.

But, if you prefer the traditional two-colume proof, this video is for you!

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.

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.

Constructing Perpendicular Line (part 2)

In this video, we construct a perpendicular line from a point to a line.  See if you can emulate the video with your own drawings.

Constructing Perpendicular Lines (part 1)

One neat use of geometry skills is construction.  Using simply a ruler and compass, you can create some important figures.  Check out this video for one example.

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.

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!

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.

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!

More from Mr. Kennedy

This exciting teacher is at it again! Here is Mr. Kennedy's video on some 3-dimensional geometry concepts. He added some cool animation. Wow, this guy is awesome.

Parallel and Perpendicular Lines

Aside from parallel lines, this chapter also deals with relationships involving perpendicular lines.  This is the link to a video explaining some fo the key concepts.

Homework Video Tutorial

This link is to a video for example 2 on page 136, a problem on using parallel lines.  Try to follow along and solve for "x".

Proving Lines Parallel

Proofs are definitely challenging for Geometry students. Here's a video that may help you on your homework!

Starring Mr. Kennedy

Hey, this teacher teaches slightly differently than I do.  He's really awesome.  Check it out.

Homework Video Tutor

Our textbook's website offers Homework Video Tutorials.  Check this out if you need help with problems from section 3-1.

Properties of Parallel Lines

We're kicking off this chapter will a new definition - transversal.  It's a line that intersects two lines at two points.  If you haven't, do check out this video: Properties of Parallel Lines.