chapter 7 Flashcards
Basic def of similar (general object)
2 objects are similar if they are the same shape but different sizes
in geo, two polygons are similar if:
- all of their corresponding angles are congruent
- The lengths of their corresponding sides are in proportion
statement of proportionality
uses letters ex CW/PI = CO/PZ = DS/ZG = WS/IG
ratios always compare _______ to another ________
polygon, polygon
ORDER…
MATTERS
similarity statement
name the shapes as you would a congruence statement than use the similarity sign
what is the similarity sign
~
what is the abbreviation for scale factor
S.F
what is a scale factor
a ratio of two corresponding sides that both have numbers ex 10/5 or 4/2
when setting up a proportion to find a missing side length, the first ratio is the ______ ________. The other ratio should include the _______ _______ and it’s cooresponding side
scale factor, unknown side
when is the only time you use the similarity symbol
in the similarity statement
AA~
shows 2 pairs of corresponding angles that are congruent
SAS~
shows 2 pairs of coorespoding sides that are in proportion and 1 pair of corresponding angles that are congruent (the angle must be included)
SSS~
shows 3 pairs of coorespoding sides that are in proportion
the type of transformation between similar polygons is called a
dialation