Rectangle Calculator
Calculate the area, perimeter, and diagonal of a rectangle using length and width.
Rectangle Dimensions
Results:
Area: 0.00 square units
Perimeter: 0.00 units
Diagonal: 0.0000 units
Step-by-Step Solution:
About Rectangles
What is a Rectangle?
A rectangle is a quadrilateral with four right angles (90°). Opposite sides are parallel and equal in length. It is one of the most common shapes in geometry and everyday life.
Key Properties
- All four angles are right angles (90°)
- Opposite sides are parallel and equal in length
- Diagonals are equal in length and bisect each other
- Has two lines of symmetry
- Special case: A square is a rectangle with all sides equal
Formulas
Area: A = Length × Width
Perimeter: P = 2 × (Length + Width)
Diagonal: d = √(Length² + Width²)
Real-World Applications
- Architecture: Windows, doors, rooms, and building layouts
- Technology: Screens, monitors, smartphones, and tablets
- Furniture: Tables, desks, beds, and picture frames
- Sports: Basketball courts, soccer fields, tennis courts
- Art: Canvas sizes, photo frames, and design layouts
Frequently Asked Questions
What's the difference between a rectangle and a square?
A square is a special type of rectangle where all four sides are equal in length. Every square is a rectangle, but not every rectangle is a square.
How do you find the diagonal of a rectangle?
Use the Pythagorean theorem: diagonal = √(length² + width²). The diagonal divides the rectangle into two congruent right triangles.
Can I calculate length if I know area and width?
Yes! Length = Area ÷ Width. This is derived from the area formula A = l × w by dividing both sides by width.
What is the perimeter of a rectangle?
The perimeter is the total distance around the rectangle. Calculate it as P = 2(length + width) or P = 2×length + 2×width.
Are the diagonals of a rectangle equal?
Yes, both diagonals of a rectangle are always equal in length. They also bisect each other, meaning they cut each other in half at the center point.
How is rectangle area used in real life?
Rectangle area calculations are used for flooring, painting walls, buying carpet, calculating room sizes, determining screen sizes, and many construction and design applications.
What units should I use for rectangle measurements?
You can use any unit (inches, feet, meters, centimeters), but ensure both length and width use the same unit. Area will be in square units, and perimeter in the same linear units.
Is a rectangle a parallelogram?
Yes, a rectangle is a special type of parallelogram where all angles are 90°. It has all the properties of a parallelogram plus the requirement of right angles.
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