There are countless different type of quadrilaterals, but all have actually several points in common: all of them have four sides, room coplanar, have actually two diagonals, and the sum of their 4 interior angles amounts to 360 degrees. This is exactly how they space alike, but what makes them different?
We know many quadrilaterals through their distinct shapes and also properties, prefer squares. Remember, if girlfriend see the word quadrilateral, the does no necessarily typical a figure with distinct properties favor a square or rectangle! In indigenous problems, be careful not come assume the a quadrilateral has parallel sides or same sides uneven that is stated.
You are watching: Why is a quadrilateral only sometimes a parallelogram?
Special Quadrilaterals
 | A parallelogram has actually two parallel bag of the contrary sides. |
 | A rectangle has actually two bag of opposite sides parallel, and also four ideal angles. The is likewise a parallelogram, because it has two bag of parallel sides. |
 | A square has two bag of parallel sides, 4 right angles, and also all four sides room equal. The is additionally a rectangle and also a parallelogram. |
 | A rhombus is characterized as a parallel with four equal sides. Is a rhombus always a rectangle? No, due to the fact that a rhombus go not need to have 4 right angles. |
 | Trapezoids only have one pair the parallel sides. It"s a type of quadrilateral the is no a parallelogram. (British name: Trapezium) |
 | Kites have 2 pairs of surrounding sides that space equal. |
We deserve to use a Venn diagram to help us team the types of quadrilaterals.
A Venn diagram offers overlapping one to show relationships in between groups that objects. Every "quadrilaterals" have the right to be separated into three sub-groups: basic quadrilaterals, parallelograms and trapezoids.
Is a rectangle constantly a rhombus? No, because all four sides that a rectangle don"t need to be equal. However, the sets of rectangles and also rhombuses execute intersect, and their intersection is the set of squares—all squares space both a rectangle and a rhombus.
We can put squares in the intersection the the 2 circles.
From this diagram, you can see that a square is a quadrilateral, a parallelogram, a rectangle, and also a rhombus!
Is a trapezoid a parallelogram? No, because a trapezoid has actually only one pair that parallel sides. The is why we must display the collection of trapezoids in a separate circle on the Venn diagram.
See more: What Does It Mean When A Man Calls A Woman Queen ? What Does It Mean When A Guy Calls You His Queen
What about kites? Kites room quadrilaterals the can it is in parallelograms. If their two pairs that sides are equal, it i do not care a rhombus, and if their angles are equal, it i do not care a square.
Related Links: Area formulas Perimeter formulas
back to top
| Homework aid | Geometry | Polygons |  |
| Search |  | |
| ·Polygon basics | ||
| ·Triangles | ||
| ·Quadrilaterals | ||
| ·Area of polygon and also circles | ||
| |