Find triangle area with pro features for base and height sides with angle or vertex coordinates get clean steps unit aware outputs and shareable links ideal for class engineering construction surveying and everyday problem solving handle tricky cases with validation tips and instant visual guidance plus batch mode history export dark theme and friendly
Base & Height: \( A=\tfrac12 bh \)Three Sides: \( A=\sqrt{s(s-a)(s-b)(s-c)} \) with \( s=\tfrac{a+b+c}{2} \)Two Sides & Angle: \( A=\tfrac12 ab\sin C \)Coordinates: \( A=\frac12 \left|x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)\right| \)Side & Altitude: \( A=\tfrac12 sh \)Check input ranges and triangle inequality to avoid invalid or degenerate cases.
If you know base and height use that. If you only have three sides use Heron's formula. With two sides and the included angle use the sine formula. With coordinates use the determinant formula.
You can pick common length units. They act as labels only. The output shows squared units such as m² or ft².
The triangle inequality must hold: the sum of any two sides must exceed the third side. Otherwise the shape is not a valid triangle.
No. Lengths and heights must be positive and the angle must be between 0° and 180° (exclusive).
Zero area typically indicates degenerate input such as collinear points or a height of zero.
Pick decimals to match your measurement accuracy. More decimals show finer detail but do not improve measurement quality.
Yes. The area is computed in squared units of your coordinate system. If your coordinates are in meters the area is in square meters.
Yes. Rearranging \( A=\tfrac12 bh \) gives \( h=\frac{2A}{b} \). Provide area and base to recover the altitude.
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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.