Download presentation
Presentation is loading. Please wait.
Published byMaurice Dorsey Modified over 8 years ago
1
(The Reverse of Lesson 5.5) I can prove the a quadrilateral is a parallelogram Day 1
2
The definition of a parallelogram is: A quadrilateral in which BOTH pairs of the opposite sides are _____________. Complete the following theorems: The opposite sides of a parallelogram are _________________________. The opposite angles of a parallelogram are _________________________. The diagonals of a parallelogram _________________________. congruent parallel congruent bisect each other
3
What would be the reverse of, ◦ If the quadrilateral is a parallelogram then the opposite sides are congruent? If the BOTH pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram. Parallelogram
4
What would be the reverse of, ◦ If the quadrilateral is a parallelogram then the opposite angles are congruent? If BOTH pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is a parallelogram. Parallelogram
5
What would be the reverse of, ◦ If the quadrilateral is a parallelogram then the diagonals bisect each other? If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. Parallelogram
6
Why do we not state the reverse of the definition? Because the definition is just that. It is not an if-then statement. So we simply write an if- then statement that fits… If the opposite sides of a quadrilateral are parallel then it is a parallelogram.
7
There is one extra way to find a quadrilateral to be a parallelogram. If ONE pair of opposite sides of a quadrilateral are parallel … AND congruent, then the quadrilateral is a parallelogram. Parallelogram
8
F AB E D C Given: ACDF is a Prove: FBCE is a
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.