Warm Up Activity
“Visualizing Similarity in right triangles”
A
D2
D1
C2
C
C1
B
1. Draw a diagonal.
2. Cut off the diagonal.
How are the triangles?
1. Label the triangles with points A,B,C
2. In one triangle, draw the altitude to the
hypotenuse
3. Mark all right angles
4. Label the new point D.
5. Label the angles D1, D2 ,C1,C2
6. Cut off the 2 triangles
Continue….
∠C=∠D1=∠D2 = Right angles
∠C1=<A Corresponding angles
∠C2=<B Triangles-Angle-Sum Th.
or
∠C2=<B Reflexive
ΔABC~ΔCBD~ΔACD
By AA ~
A
C1
A
C
D1
D2
C2
• Label the back of the triangles with the letters that
represent their angles.
How can you prove that the 3 triangles are similar?
8. Align the 3 triangles as is shown.
Name the postulate or theorem you can use to prove
triangles similar
Template for rectangles