Download Guided Notes - Proving Triangles are Similar

Geometry
Guided Notes
Proving Triangles are Similar
Name: _____________________________
Date: __________________ Period: _____
_____________________ Similarity Postulate - if two angles of one triangle are congruent to two angles of
another triangle, then the two triangles are similar.
Examples of AA Similarity Postulate
Decide whether the triangles are similar, not similar or cannot be determined.
Which triangles are similar to ΔABC? Explain.
7.
a.
b.
c.
_______________________ Similarity Theorem - If corresponding sides of two triangles are proportional, then
the two triangles are similar.
Examples of SSS Similarity Theorem
Decide whether the triangles are similar, not similar or cannot be determined. (smallest to smallest, medium to
medium, largest to largest)
Geometry
Guided Notes
Proving Triangles are Similar
Name: _____________________________
Date: __________________ Period: _____
Which triangles are similar to ΔABC? Explain.
1.
a.
b.
c.
________________________ Similarity Theorem - If an angle of one triangle is congruent to an angle of a
second triangle and the lengths of the sides including these angles are proportional, then the triangles are
similar.
Examples of SAS Similarity Theorem
Which triangles are similar to ΔABC? Explain.
3.
a.
b.
c.
Putting it all together
Determine whether the triangles are similar. If they are write the similarity statement and state the postulate or
theorem.
Geometry
Name: _____________________________
Guided Notes
Proving Triangles are Similar
Date: __________________ Period: _____
Determine whether the triangles are similar. If they are write the similarity statement and state the postulate
or theorem.
You are given the ratios of the lengths of the sides of DABC and DDEF. Choose the cases where ΔABC ~ ΔDEF.
ΔABC 4 : 8 : 10
Solve for x.
Determine if the triangles are similar and state the postulate or theorem that justifies your answer. If the
triangles are similar, find the value of x. All lengths are in centimeters and diagrams are not drawn to scale.