Math

Geometry calculator

Use the Geometry calculator for fast, clear results with formulas and practical examples.

Geometry calculator

Result60
Perimeter32

What this calculator answers

Calculate area and perimeter for a rectangle, right triangle, or circle using only the dimensions required by the selected shape.

Variables, defaults, and limits

Shape
Shape is a choice input. The displayed starter value is Rectangle; it is an example, not a hidden assumption.
Default: Rectangle
Accepted values: The field has no narrower HTML limit, but it must still satisfy the documented formula domain and produce a finite result. Available choices: Rectangle, Circle, rightTriangle.
Width
Width is a number input. The displayed starter value is 10; it is an example, not a hidden assumption.
Default: 10
Accepted values: Minimum: 0.000001. Numeric entries must be finite and unambiguous.
Height
Height is a number input. The displayed starter value is 6; it is an example, not a hidden assumption.
Default: 6
Accepted values: Minimum: 0.000001. Numeric entries must be finite and unambiguous.
Radius
Radius is a number input. The displayed starter value is 5; it is an example, not a hidden assumption.
Default: 5
Accepted values: Minimum: 0.000001. Numeric entries must be finite and unambiguous.

Formula and calculation rule

A ∈ {x₂x₃; x₂x₃/2; πx₄²}; selector=x₁; x₁=Shape; x₂=Width; x₃=Height; x₄=Radius

Geometry calculator evaluates the registered expression “A ∈ {x₂x₃; x₂x₃/2; πx₄²}; selector=x₁; x₁=Shape; x₂=Width; x₃=Height; x₄=Radius” with the validated inputs. Full calculation precision is retained until the result is formatted for display.

Worked examples

Geometry calculator evaluated example 1

Use the page’s labelled starter inputs to verify Geometry calculator.

Inputs
  • Shape: Rectangle
  • Width: 10
  • Height: 6
  • Radius: 5

Evaluated result: 60

Geometry calculator evaluated example 2

Select circle and enter radius = 12.5 to calculate its area and circumference; width and height are not used in this mode.

Inputs
  • Shape: Circle
  • Width: 10
  • Height: 6
  • Radius: 12.5

Evaluated result: 490.8738521234

Assumptions

  • Geometry calculator uses the visitor-entered values exactly as labelled; it does not retrieve private records or current rates.
  • The calculation is limited to the declared relationship: A ∈ {x₂x₃; x₂x₃/2; πx₄²}; selector=x₁; x₁=Shape; x₂=Width; x₃=Height; x₄=Radius.
  • Intermediate values are not rounded; display rounding is applied only at the presentation boundary.
  • The deterministic calculation runs locally and does not upload calculator inputs to the application API.
  • The result is an educational arithmetic result and excludes facts that are not represented by an input.

Validation and boundaries

  • Every visible required input must be present; a missing value is never replaced with zero.
  • NaN, positive or negative infinity, unsafe overflow, and a non-finite final result are rejected.
  • Field-specific minimums, maximums, and choices apply to Shape, Width, Height, Radius.
  • Zero, negative values, and discrete counts are accepted only when the displayed field definition permits them.

Review and correction links

Common mistakes

  • The tool covers only the three displayed planar shapes, assumes every entered dimension uses one consistent length unit, and does not model composite shapes, tolerances, or unit conversion.
  • Confirm the meaning and unit of Shape, Width, Height, Radius before calculating; a numerically valid value can still use the wrong convention.
  • Do not round intermediate values when checking the result, because early rounding can change the last displayed digits.
  • Changing an unstated real-world assumption does not change the calculator until the corresponding displayed input is changed.
  • Use the result as the answer to the displayed mathematical question, not to a different word problem with hidden conditions.

Frequently asked questions

Why are width and height ignored in circle mode?
A circle in this tool is fully defined by its radius, so its area is πr² and its circumference is 2πr; rectangle and triangle dimensions are inactive.
What question does Geometry calculator answer?
Use the Geometry calculator for fast, clear results with formulas and practical examples. The implemented relationship is A ∈ {x₂x₃; x₂x₃/2; πx₄²}; selector=x₁; x₁=Shape; x₂=Width; x₃=Height; x₄=Radius.
Which inputs does Geometry calculator use?
It uses the visible fields Shape, Width, Height, Radius. No hidden value is substituted for an omitted required input.
What happens when Geometry calculator receives an invalid or extreme value?
The page rejects missing, ambiguous, out-of-range, or non-finite values and refuses to display a non-finite result.
Why can Geometry calculator differ from another result?
Different unit conventions, endpoint policies, fee or rate assumptions, formula domains, and premature rounding can produce a different answer.
Can I use Geometry calculator as professional advice?
No. It answers the displayed mathematical question and cannot account for omitted real-world facts.
How can I verify the Geometry calculator result?
Recalculate the two evaluated examples without rounding intermediate values and compare the declared formula or convention with Euclidean geometry.

Source and review scope

Euclidean geometry

Scope: Euclidean geometry is used to check the formula, definition, or convention relevant to Geometry calculator. The citation does not supply current personal, lender, tax, medical, or market data.

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