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Chapter 10 - Similarity. By: Ashley and Rachele. Section 10-1. A proportion is a statement that two ratios are equal. Example: a:b = c:d. To prove 2 polygons similar, corresponding angles must all be congruent and size must be proportionate. . Section 10-2 Proving Triangles Similar.
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Chapter 10 - Similarity By: Ashley and Rachele
Section 10-1 • A proportion is a statement that two ratios are equal. • Example: a:b = c:d
To prove 2 polygons similar, corresponding angles must all be congruent and size must be proportionate.
Section 10-2 Proving Triangles Similar • AA, SAS, SSS • If two angles of one triangle are congruent to two angles of another triangle then the triangles are similar. – AA • If an angle of one triangle is congruent to an angle of a second triangle, and the sides including the two angles are proportional, then the triangles are similar. – SAS • If the corresponding sides of two triangles are proportional, then the triangles are similar. - SSS
Section 10-3 • Geometric mean !
Section 10-4 proportions and similar triangles Slide Splitter Proportions
Section 10-5 / 10-6 • Similarity ratios 2 : 6 1 : 3 Perimeter ratio 8 : 24 1 : 3 Area ratio (in2) 4 : 36 (in3) 1 : 9 Volume ratio (in3) 8 : 216 1 : 27
Which of the following is this showing? SAS SSS AA None
2. What is the geometric mean of 8 & 18 ? A.+/- 12 B. 12 C. +/- 144 D. 144
3. Which of the following is this showing? SAS SSS AA None
Can you use SAS to prove that the triangles pictured below similar? Yes No
5. What is the value of x? 18 2 3 24
6. Are the following polygons similar? Yes B. No
If you couldn’t get those, well that is sad ): No offense! LOOK AT THE BRIGHT SIDE YOUR HALF WAY DONE WITH THE QUESTIONS (:
9. If a 5 ft. 3in. man is casting a 6 ft. shadow and a building is casting a 20 ft. shadow. How tall is the building?
Solve for x. 10.