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Geometry 9.7 Perimeter and similarity. MORE PROPORTIONS. To solve a proportion you can only have one variable. 8 x 15 12. 27 45 z+3 z. =. =. x y 9 16. Can’ t solve No can do shamu. =. New twist?.
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To solve a proportion you can only have one variable. 8 x 15 12 27 45 z+3 z = = x y 9 16 Can’ t solve No can do shamu =
New twist? Not only can you make proportions with sides but you can also use the entire perimeter!
B Q I can’t solve anything with this information 4 5 z c y But they will tell you P of ΔPQR = 36 3 A R x P
B Q P of ΔPQR = 36 4 5 So what is P of ΔABC = z c y 3 5 + 4 + 3 = 12 A R x P
B Q P of ΔPQR = 36 4 P of ΔABC = 12 5 z c y 12 3 = 3 x 36 A R 12x = 108 x X = 9 P
B Q Now it is just like our previous homework 4 5 z 3 4 c = y z 9 3 A R 3 5 = y 9 9 P
Homework 2 They will ask for a SCALE FACTOR between two triangles. This is just the ratio of one triangle to the other.
Homework 2 Pick a side from the first triangle and put it over the corresponding side from the second triangle. 1st is on top 2nd on bottom Then reduce
G V Scale factor of ΔFGH to ΔUVW is… 9 12 H 15 6 3 20 = 6 5 10 F W 10 U
Q Scale factor of ΔJKL to ΔPQR is… 5 K 6 P 10 4 2 8 12 R = 4 1 J L 8
G V Scale factor of ΔUVW to ΔFGH is… 9 12 H 15 5 20 10 = 6 6 3 F W 10 U