Perimeter Calculator
Calculate the perimeter of various geometric shapes with precise mathematical formulas
Calculate Perimeter
Perimeter Result
Formula used: P = 4a
Example Calculation
Rectangle Example
Given: Length = 10 units, Width = 6 units
Formula: P = 2(l + w)
Calculation: P = 2(10 + 6) = 2(16) = 32 units
Circle Example
Given: Radius = 5 units
Formula: P = 2πr
Calculation: P = 2π(5) = 10π ≈ 31.416 units
Common Formulas
P = 4aP = 2(l + w)P = a + b + cP = 2πrP = n × aPerimeter Tips
Perimeter is the distance around a closed figure
Always expressed in linear units (cm, m, inches, etc.)
For irregular shapes, sum all side lengths
Circle perimeter is called circumference
π ≈ 3.14159 for circle calculations
Understanding Perimeter
What is Perimeter?
Perimeter is the boundary of a closed geometric figure. It may also be defined as the outer edge of an area, simply the longest continuous line that surrounds a shape. The name itself comes from Greek perimetros: peri meaning "around" + metron, understood as "measure".
Key Properties
- •Expressed in distance units (meters, feet, inches, etc.)
- •Always a positive value
- •Sum of all boundary lengths
- •One-dimensional measurement
Common Applications
- •Fencing: Calculate material needed to enclose an area
- •Framing: Determine border material for pictures or rooms
- •Architecture: Calculate trim and molding lengths
- •Sports: Track and field measurements
- •Manufacturing: Calculate edge treatments
Remember: Perimeter vs Area - Perimeter measures the boundary, while area measures the space inside the boundary.
Shape Categories
Polygons
Closed figures with straight sides
- • Triangle (3 sides)
- • Square (4 equal sides)
- • Rectangle (4 sides)
- • Pentagon (5 sides)
- • Hexagon (6 sides)
- • Regular polygons
Curved Shapes
Figures with curved boundaries
- • Circle
- • Ellipse
- • Circle sector
- • Annulus (ring)
Special Quadrilaterals
Four-sided figures with special properties
- • Parallelogram
- • Rhombus
- • Trapezoid
- • Kite