Do Now Make sure you have the following Lined paper Ruler Partner with a book 3-30-09 If you were told the ratio from figure A to B was 150% and the side length of A was 2 inches. How long is the side length of figure B.

Objective Look at the side splitter theorems. 3-30-09

Look at the side splitter theorems.

Experiment time You and a partner will have 15 minutes to work on the experiment on page 308. You should each complete Part 1A of the experiment in your notebook. Use lined paper to make the parallel lines and measure the distances between lines and the point. 3-30-09

You and a partner will have 15 minutes to work on the experiment on page 308.

You should each complete Part 1A of the experiment in your notebook. Use lined paper to make the parallel lines and measure the distances between lines and the point.

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Take a minute to organize your conclusions. 3-30-09

Take a minute to organize your conclusions.

Label one of your from #1 triangles like this. Measure AB and AD. What do you find? Measure AE and AC. What do you find? 3-30-09 A B C D E

Measure AB and AD. What do you find?

Measure AE and AC. What do you find?

Conclusions 3-30-09

Theorem 4.1 The Parallel Side Splitter Theorem If the segment with endpoints on the two sides of a triangle is parallel to the third side then… The segment splits the sides it intersects proportionally The ratio of the length of the side of the triangle to the length of the parallel segment is the common ratio

If the segment with endpoints on the two sides of a triangle is parallel to the third side then…

The segment splits the sides it intersects proportionally

The ratio of the length of the side of the triangle to the length of the parallel segment is the common ratio

Theorem 4.2 The Proportional Side-Splitter Theorem If the segment with endpoints on two sides of a triangle splits those sides proportionally then the segment is parallel to the third side.

If the segment with endpoints on two sides of a triangle splits those sides proportionally then the segment is parallel to the third side.

H/W Pg 311 #1-5 3-30-09

Pg 311 #1-5

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