Unit 9 Lesson 6.2A: Parallelograms CCSS Lesson Goals G-CO 11: Prove theorems about parallelograms. State the definition and properties of a parallelogram Use the properties of a parallelogram to solve for missing lengths and angle measures. ESLRs: Becoming Effective Communicators, Competent Learners and Complex Thinkers

Parallelograms A quadrilateral with both pairs of opposite sides parallel. both pairs of opposite sides congruent. both pairs of opposite angles congruent. supplementary consecutive angles. diagonals that bisect each other. This is the definition

Parallelograms A quadrilateral with definition A quadrilateral with both pairs of opposite sides parallel. A B D C

Parallelograms A quadrilateral with property A quadrilateral with both pairs of opposite sides congruent. A B D C

Parallelograms A quadrilateral with property A quadrilateral with both pairs of opposite angles congruent. A B D C

Parallelograms A quadrilateral with diagonals that bisect each other. property A quadrilateral with diagonals that bisect each other. A B C D E

Parallelograms A quadrilateral with supplementary consecutive angles. property A quadrilateral with supplementary consecutive angles. A B D C

Example

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Example Find JH and LH K J 6 6 8 8 L G H

Example Find the other angle measures K J 105o 105o G H

Example Find the other angle measures K J 75o 105o 105o G H

Example Find the other angle measures K J 75o 105o 105o 75o G H

You Try K J G H

Example Find the value of each variable in the parallelogram

Example Find the value of each variable in the parallelogram

Example Find the value of each variable in the parallelogram

Summary Create a mnemonic or acronym to remember the characteristics of a parallelogram.

Today’s Assignment p. 333: 1 – 11, 20 – 25, 27 – 39 o