1. Altitudes–On- Hypotenuse Theorem
NOTES 9.3
Altitudes–On- Hypotenuse Theorem A B C D

2. Three similar triangles: small, medium and large.
Altitude CD drawn to hyp. of △ABC C A B D
Three similar triangles are formed. A C B D A D C B C
Three similar triangles: small, medium and large.

3. Theorem 68:
If an altitude is drawn to the hypotenuse of a right triangle then,
The two triangles formed are similar to the given right triangle and to each other.
Δ ADC ~ Δ ACB ~ Δ CDB A B C D

4. 3 IMPORTANT PROPORTIONS

5. If AD = 3 and DB = 9, find CD.

6. If DB = 21 and AC = 10, find AC.