PIB GEOMETRY 5-1: Properties of Parallelograms

Warm Up

The results are in! I will now be holding a math study group every Monday at 3:30 in room 201! This will be very informal. I will be there to answer questions, but more importantly, it will be a place where students can collaborate with each other on anything math-related.

Chapter 5 – Quadrilaterals: Objectives 5-1: Apply definitions and theorems about parallelograms 5-2: Prove quadrilaterals are parallelograms 5-3: Apply theorems about parallel lines and midpoint theorems for triangles 5-4: Apply definitions and identify properties of rectangle, rhombus and square 5-5: Apply definitions and properties of trapezoids. geometry/calendar geometry/calendar

5-1 Definitions A quadrilateral is: Notation: A parallelogram is: Notation

Theorem 5-1: Opposite sides of a parallelogram are congruent. Already proved! (in 4-3 homework, #5).

Theorem 5-2: Opposite Angles of a parallelogram are congruent. Proved (mostly) in warmup!

Theorem 5-3: The diagonals of a parallelogram bisect each other Proved in tonight’s homework

Example – Solve for the variables in the following parallelograms

Solve for x and y in ABCD

5-1 Homework p. 169: #5-11 odd, 15, odd, 20, 24