Geometry Tool
Plane Geometry Reference
Quick reference for 2D shape areas and perimeters.
Square
AreaA = a²
Perimeter / CircumferenceP = 4a
Where 'a' is the side length.
Rectangle
AreaA = lw
Perimeter / CircumferenceP = 2(l + w)
Length 'l' and Width 'w'.
Circle
AreaA = πr²
Perimeter / CircumferenceC = 2πr
Where 'r' is the radius.
Triangle
AreaA = 1/2 bh
Perimeter / CircumferenceP = a + b + c
Base 'b' and Height 'h'.
Parallelogram
AreaA = bh
Perimeter / CircumferenceP = 2(a + b)
Base 'b' and Height 'h'.
Trapezoid
AreaA = 1/2 (a+b)h
Perimeter / CircumferenceP = a + b + c + d
Parallel sides 'a' and 'b'.
Ellipse
AreaA = πab
Perimeter / CircumferenceP ≈ π(3(a+b) - √((3a+b)(a+3b)))
Semi-major 'a' and semi-minor 'b'.
Regular Polygon
AreaA = 1/2 n s a
Perimeter / CircumferenceP = n s
n sides, length s, apothem a.
Geometry is the foundation of all design.
# About This Calculator
Plane Geometry deals with flat shapes like lines, circles, and triangles—shapes that can be drawn on a piece of paper.
This guide lists the formulas for **Area** (space covered) and **Perimeter** (distance around) for the most frequent 2D shapes.
Frequently Asked Questions
Is Plane Geometry Reference free to use?+
Yes, Plane Geometry Reference on Matheric is completely free to use. We believe in accessible education and utility for everyone.
How accurate is Plane Geometry Reference?+
We use standard mathematical formulas and high-precision computing algorithms to ensure results for Plane Geometry Reference are accurate for academic and professional use.
Can I use Plane Geometry Reference on my phone?+
Yes! Plane Geometry Reference is fully responsive and optimized for all devices, including smartphones, tablets, and desktops.
Do you save my data?+
No. We prioritize your privacy. All calculations are performed in your browser or temporarily processed, and we do not store your personal input data.
How do I report a bug?+
If you notice any issues with Plane Geometry Reference or have suggestions for improvement, please contact us via the link in the footer. We value your feedback!
Can I request a new feature?+
Absolutely. We are constantly expanding our toolset. Feel free to reach out with your requests, and we might build it next!