90 likes | 234 Views
7-3 Proving Triangles Similar. One Postulate Two Theorems. Postulate 8-1. Angle-Angle Similarity (AA~) Postulate If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar. Theorem 8-1. Side-Angle-Side Similarity (SAS~) Theorem
E N D
7-3Proving Triangles Similar One Postulate Two Theorems
Postulate 8-1 Angle-Angle Similarity (AA~) Postulate • If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.
Theorem 8-1 Side-Angle-Side Similarity (SAS~) Theorem • If an angle of one triangle is congruent to an angle of a second triangle, and the sides including the two angles are proportional, then the triangles are similar.
Theorem 8-2 Side-Side-Side Similarity (SSS~) Theorem • If the corresponding sides of two triangles are proportional, then the triangles are similar.
#1 Using the Similarity Theorems What theorem or postulate state that the two triangles similar? V W 450 S 450 1. 1. R B 2. 2. 3. 3.
#2 Using Similarity Theorems • Write a similarity statement for the two triangles. G 9 A B 8 8 6 6 E F 12 C
#3 Finding Lengths in Similar Triangles • Find the value of x in the figure. 6 8 12 x
Indirect Measurement You can use indirect measurement to find lengths that are difficult to measure directly. One method of indirect measurement uses the fact that light reflects off a mirror at the same angle at which it hits the mirror.
(Set up proportion) Before rock climbing ,Darius wants to know how high he will climb. He places a mirror on the ground and walks backward until he can see the top of the cliff inn the mirror. What is the height of the cliff?