Download Lesson 3.04 KEY Main Idea (page #) DEFINITION OR SUMMARY

Lesson 3.04 KEY
Main Idea (page #)
DEFINITION OR SUMMARY
Similar (P1)
Figures that have the same shape, but different sizes
EXAMPLE or DRAWING
Symbol is ____~______
When the corresponding angles of two or more triangles are
Angle-Angle Similarity Postulate
congruent, the triangles are similar (P2).
Order is important when you talk about congruency. It is
Corresponding Parts (P1-2)
even more important when you discuss similarity.
Orientation (P2)
THEOREMS to identify
Similar Figures
1) Side-Angle_Side
Similarity Postulate
(SAS) (P3)
The positioning of the figures
If corresponding angles are equal in two or more triangles,
and the sides around that angle have the same simplified
fraction, then the triangles are similar.
If all three corresponding sides of two or more similar
2) Side-Side-Side Similarity
Theorem (SSS)
triangles have the same simplified fraction then the triangles
are similar. (P5)
Saying ΔABC ~ ΔDEF is not the same as saying
ΔABC ~ ΔDFE.
Lesson 3.04 KEY
Look for a segment in the middle of the triangle. Is that
Triangle Proportionality
Theorem (P7)
segment parallel to one of the sides? If so, the segments on
the two sides of the triangle can be written as a proportion.
Central Similarity (pg. 9)
1) Triangle Altitude
Similarity Theorem
If two triangles are similar, the corresponding altitudes are
proportional to each set of corresponding sides.
If two triangles are similar, the corresponding medians are
2) Triangle Median Similarity
Theorem
proportional to each set of corresponding sides.
If two triangles are similar, the corresponding angle bisectors
3) Triangle Angle Bisector
Similarity Theorem
are proportional to each set of corresponding sides.
When two triangles are similar, the perimeters are
4) Proportional Perimeter
Theorem
proportional to their corresponding sides.