Download The corresponding sides of the figures are of equal proportion.

13­1 & 13.2 The SSS, AA & SAS Similarity Theorem
1. What does it mean for two figures to be similar?
The corresponding sides of the
figures are of equal proportion.
2. If two triangles are similar then the sides are
in equal PROPORTION and the corresponding angles are CONGRUENT.
3. Three ways to show that two triangles are similar
to each other are Side Side Side, Angle Angle, & Side Angle Side.
SSS Similarity Theorem: If three sides of one triangle are proportional to three sides of a second triangle, the two triangles are similar.
5. Are the triangles below similar?
5. Are the triangles below similar?
6. Is a right triangle with sides 3, 4, 5 and 5, 12, 13 similar? Justify your answer.
AA Similarity Theorem:
If two angles of one triangle are congruent to two angles of another, then the two triangles are similar.
8. Are the triangles below similar?
B
A
E
CF
D
8. Are the triangles below similar?
Y
X
A
ZB
C
SAS Similarity Theorem: If, in two triangles, the ratios of two pairs of corresponding sides are equal and the included angles are congruent, the triangles are similar.
10. Are the triangles below similar?
A
M
N B
L
C
10. Are the triangles below similar?
A
M
L
N B
C
11. A meter stick casts a shadow 70 cm long at the same
time that a tree casts a shadow 3.4 meters long. How tall
is the tree? Draw a picture to help you.
The two triangles below are similar, find the following measures: w, x, y, z
Solve by setting up proportions!
13. The triangles below are similar with corresponding sides parallel. Find the ratio of similitude. Write a similarity statement using the correct order of vertices!