Quadrilateral
Definition of Quadrilateral
- A quadrilateral is a four-sided polygon.
Examples of Quadrilateral

More about Quadrilaterals
- Parallelogram: A quadrilateral with two pairs of opposite sides parallel.
- Rhombus: A parallelogram with four congruent sides.
- Rectangle: A parallelogram with four right angles.
- Square: A parallelogram with four congruent sides and four right angles.
- Trapezoid: A quadrilateral with only one pair of parallel sides.
Solved Example on Quadrilateral
A quadrilateral with vertices (0, 0), (5, 0), (8, 4) and (3, 4) forms a ________.
Choices:
A. Rhombus
B. Square
C. Rectangle
D. Trapezoid
Correct Answer: A
Solution:
Step 1: Let (0, 0), (5, 0), (8, 4), and (3, 4) be A, B, C, and D respectively.
Step 2: Use the distance formula, 
Step 3:
Step 4: 
Step 5: 
Step 6: 
Step 7: 
Step 8: 
Step 9: The lengths of the sides AB, BC, CD, and DA are equal and the lengths of the diagonals AC and BD are not equal in quadrilateral ABCD.
Step 10: So, ABCD is a rhombus.
Related Terms for Quadrilateral
- Polygon
- Parallelogram
- Rhombus
- Rectangle
- Square
- Trapezoid
- Congruent
- Parallel
Additional Links for Quadrilateral