90 likes | 253 Views
2/15 Geometry Bell Ringer. Given that DE // AB, find EB and AB. Homework: Similarity Proofs Day 1 Independent Practice. 2/15 News and Notes. Perfection Award: 1 st Period HW Checked? Quiz Make-ups and retakes today in 218 Need to serve a detention? Today in 218. Quiz Make-ups.
E N D
2/15 Geometry Bell Ringer Given that DE // AB, find EB and AB. Homework: Similarity Proofs Day 1 Independent Practice
2/15 News and Notes • Perfection Award: 1st Period • HW Checked? • Quiz Make-ups and retakes today in 218 • Need to serve a detention? Today in 218
Quiz Make-ups • 1st: Brishanika, Kenneth, • 7th: Kaneisha, D’Antoinette, Selena, Tatyana, Leslie • 8th: Cristian E, Angela, Coraima, Daniel, Lorena, Brittany, Jasmine Z
Today’s Goal • Use our Similarity Postulates to prove two triangles are similar. • What were our 3 Similarity Postulates? • SSS, SAS, and AA
In order for two triangles to be similar, what must be true? • 1. Corresponding angles congruent • 2. Corresponding sides proportional
Example 1 • This example is just to get us comfortable with the process of a proof. • Given: AC = 5, BE = 10, CB = 3, DE = 6, Prove: ∆ACB~ ∆BED Step 1: Mark Given Information Step 2: Check sides. E C A B D
Example 2 • Given: Prove: ∆ACB~ ∆BED Step 1: Mark Given Information Step 2: Check sides. E C A B D
Guided Practice • Let’s take it up a notch - • Given: AC = BC = 6cm EC = DC = 4cm Prove: ∆ACB~ ∆ECD 1. AC = BC = 6cm; EC = DC = 4 1. Given 2. 2. Substitution 3. 3. Vertical Angles 4. ∆ACB~ ∆ECD 4. SAS
Independent Practice • If you finish, here’s the bonus question: