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Not all things with four sides have to be squares or rectangles! We will now broaden our understanding of quadrilaterals!
"Quad" means "four" and "lateral" means "line." A quadrilateral is literally a shape with four sides (lines) and four angles. Let's learn the difference between concave and convex quadrilaterals as well as trapezoids, parallelograms, and ...
How about this: we are given a 4-sided shape and asked to determine whether its properties qualify it to be called a quadrilateral (or category of quadrilaterals). Check it out.
Is a kite a quadrilateral? Is it a rhombus? A parallelogram? Let's find out.
Take a look at the given data and determine what type of quadrilateral we have.
Proving that a figure is a parallelogram if and only if opposite sides are congruent
Proving that a quadrilateral is a parallelogram if and only if its diagonals bisect each other
Showing that opposite angles of a parallelogram are congruent
Proving that the diagonals of a rhombus are perpendicular
Showing that we can find the area of a rhombus by taking half the product of the lengths of the diagonals
Guess what's interesting about the opposite sides of a parallelogram? That's right....they are parallel! Let's find the area--base times height
Proving whether a special quadrilateral can exist
Proof that the diagonals of a rhombus are perpendicular bisectors of each other