1. Classifying Quadrilaterals
“…geometric shapes are the alphabet in which the book of nature is written." -Galileo
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Type your name and send:

2. Objectives
Define what parallelograms, kites, rectangles, squares, rhombi, and trapezoids are.
Sort and classify quadrilaterals.
Determine which shapes are and are not quadrilaterals, given examples.
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3. What is a Quadrilateral?
A quadrilateral is a two-dimensional figure formed by connecting four segments endpoint to endpoint with each segment intersecting exactly two others. It also has four sides and four angles.
A four sided polygon.
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4. Types of Quadrilaterals
Trapezoid
Parallelogram
Square
Rectangle
Kite, Dart
Rhombus
Scalene
Which one is NOT a quadrilateral?
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5. Classification of Quadrilaterals
A concave quadrilateral contains at least one angle that is >180o.
A quadrilateral is convex if each vertex lies in the interior of the opposite angle.
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6. Name that Quadrilateral! (No points for this name!)
A square is a quadrilateral with all sides and angles equal.
If all quadrilaterals have 360o total, what is the angle of each vertex in a square?
Ans: 90 degrees
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7. Name that Quadrilateral!
A quadrilateral with all angles equal is a rectangle.
A quadrilateral with all sides equal is a rhombus.
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8. In Euclidean geometry, a rhombus or rhomb is a convex quadrilateral whose four sides all have the same length. The rhombus is often called a diamond, after the diamonds suit in playing cards, or a lozenge, though the latter sometimes refers specifically to a rhombus with a 45° angle.
Every rhombus is a parallelogram, and a rhombus with right angles is a square. (Euclid's original definition and some English dictionaries' definition of rhombus excludes squares, but modern mathematicians prefer the inclusive definition.)[1]
The English word “rhombus” derives from the Ancient Greek ῥόμβος (rhombos), meaning spinning top. The plural of rhombus can be either rhombi or rhombuses.
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9. Name that Quadrilateral!
Trapezoid
A quadrilateral with at least one pair of parallel sides is a t……oid.
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10. Name that Quadrilateral!
A quadrilateral with both pairs of opposite sides parallel and equal in length is known as a p….gram.
Parallelograms can be considered special cases of trapezoids, since they have a least one pair of parallel sides.
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11. Name that Quadrilateral!
A quadrilateral with two separate pairs of equal adjacent sides is commonly called a ????.
However, if the kite is concave, a dart is a more appropriate term.
This is a dart:
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12. Are They Quadrilaterals?C B
Examples of shapes or curves that are not classified as quadrilaterals. They do not follow the definition of a quadrilateral. Can you give a reason why?
It crosses over itself intersecting more than two other segments.
There are four sides, but the segments are not straight.
Same as B.
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13. LO:To classify quadrilaterals
I need more practice to help me understand this and I made lots of mistakes. B
I am beginning to understand this and I got many of them correct. C
I really understand this and I got most of them correct.
Follow up activity

14. Work in pairs. You will be given the name of a shape
Work in pairs. You will be given the name of a shape. For each shape, you must write as many facts as you can that are true about the shape in your book. For example you can say that a scalene triangle has three sides. You can not say that it does not have four sides.
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