What is a Rhombus?

A rhombus is a quadrilateral, which means it is a closed figure with four sides
Arrows are used to show that if we extend opposite sides we get parallel lines
The || symbol means 'parallel'
Parallel lines lie in the same plane, but never intersect
A line above the two letters represents a line segment, or side
The equal sign with a squiggly line over it means 'congruent'
Congruent sides have the same length and are identified on the figure with matching dash marks
The slanted 'L' symbol indicates an angle, and opposite angles are congruent, which means they have the same measure

1. As long as it's a closed figure with four sides, it's a quadrilateral!
2. Remember that 'congruent' just means 'the same'
3. Parallel lines will never intersect, even if you extend them out forever
4. Congruent sides have the same length
5. Congruent angles have the same measurement
6. Opposite sides and angles are across from each other in the figure
1. Rhombuses fall into a couple other categories of four-sided figures
1. Note that a rhombus is also a closed four-sided figure!
1. Note that not all four sides of a parallelogram need to be the same length
2. So a rhombus is a special type of parallelogram with four equal sides
3. Parallel lines will never intersect, even if you extend them out forever
4. Congruent sides have the same length
5. Congruent angles have the same measurement

What is a rhombus?