Download similarity triangles and midsegment notes 3-18

3rd block: D.E.A.R 15 minutes
• Midterm is on Monday 3/25 for 3rd block & 4th
block, so you could be studying during D.E.A.R
• Tips: make flashcards, study
vocabulary/concepts, and work on practice
problems
Do now 3-18-13
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Midterm is Friday 3/22/13 for 2nd block
Midterm is Monday 3/25/13 for 3rd & 4th block
Lines and angles questions:
1. line c is parallel to d, with corresponding
angles being 55 degrees and (3w – 2), what is
the value of w and what is the degree?
• 2. pg. 163 #52
Unit 5
Similarity & right triangle
similarity
Where are proportions used?
• Math
• Cooking
• Statistics in games
Purpose of unit 5
• Prove line intersecting a triangle is
parallel to one of the sides, then it
divides the other two sides of that
triangle proportionally
• Prove that if a line divides two sides of a
triangle proportionally, then it is parallel
to the 3rd side
• Vocabulary to know: parallel lines,
similar triangles, angle-angle similarity,
proportion
Video to discuss similarity, right
triangles, and other triangle concepts
• Section B: Right Triangles, Altitudes,
the Pythagorean Theorem, and You
• http://app.discoveryeducation.com/
search?Ntt=section+B%3A+Right+tri
angles%2C+altitudes%2C+the+pytha
gorean+theorem+and+you
Triangle similarity parts
• Angle – angle similarity postulate pg. 450
– Uses: If…..then statement
• Side-angle-side similarity pg. 451
– Sides must surround angle OR angle between
sides
• Side-side-side similarity pg 451
– Corresponding sides of 2 triangles are
proportional then similar
To determine similarity in 2 triangles
• Measure the side lengths and show
proportional
• OR
• Use triangle sum theorem to find missing
angle measures
Practice
• Pg 451 AA, SSS, SAS
• Proof practice (statement/reason table)
– Pg. 453 discuss example
– Pg. 453 try one by self or with partner
midpoint & proportionally
• Investigating midsegments pg. 284
• Triangle midsegment thm pg. 285
– Together do problem task (pg 6 unit 5 packet)
• Problem #1 pg. 286
• Lesson check pg. 288
j.mp/msburns
• j.mp/msburns choose Geometry Syllabus,
assignment table
• 7-4 challenge due 3/20 – extra credit
• 7-5 challenge due 3/20 – extra credit
• Tips for midterm: make flashcards, study
vocabulary/concepts, and work on practice
problems
Summary 3-18-13
• In Geometry we need to prove answer,
therefore where else do we need to prove
things, explain? (name specific places)