Similarity in Right Triangles Geometry 8-4
Supplies One sheet of computer paper Scissors Exploration
Cut a sheet of paper into a rectangle (fold to create a perfect rectangle) Don’t be lazy and use the whole sheet of paper Exploration
Draw a diagonal on the paper, and cut Exploration
Fold and cut along the altitude of one triangle Exploration
Label the angles as shown 5 7 2 4 6 8 9 1 3 Exploration
Exploration Compare the angles on the three triangles 5 7 2 4 6 8 9 1 3 Exploration
Exploration Which angles are congruent to angle 1? 4 and 7 6 and 8 5 and 9 5 7 2 4 6 8 9 1 3 Exploration
Exploration So... What is true about all three triangles? They are similar 5 7 2 4 6 8 9 1 3 Exploration
Write a similarity statement C A B D Exploration
Geometric Mean – A proportion with the same variable in each fraction as shown Geometric Means
Example
Theorem and corollaries
Theorem and corollaries
Example
Example
Example
Example
Practice
Practice
Practice
Practice
Practice
Practice
Practice
Practice
Practice
Pages 442 – 444 15, 18, 30 – 36 even, 42, 44, 50, 52, 62 - 64 Homework