11 FOCUSED TOOLS
Triangle calculators
Find triangle sides, areas and perimeter from different known measurements.
Choose the right calculation
Use base and perpendicular height for the simplest area calculation. With three known sides, Heron’s formula avoids measuring height. Triangle side lengths must satisfy the triangle inequality before any area result is meaningful.
Find a tool for your question
Triangle Area Calculator
Calculate a triangle’s area using a base and perpendicular height.
Pythagorean Theorem Calculator
Find the hypotenuse of a right triangle from its two shorter sides.
Herons Formula Calculator
Find triangle area when all three side lengths are known.
Equilateral Triangle Area Calculator
Find the area of a triangle with three equal sides.
Triangle Perimeter Calculator
Add the side lengths of a valid triangle.
Right Triangle Leg Calculator
Recover a right triangle’s missing leg from the hypotenuse and another leg.
Triangle Area From Two Sides Calculator
Find a triangle’s area from two sides and their included angle.
Triangle Altitude Calculator
Recover a triangle’s perpendicular height from area and base.
Triangle Inradius Calculator
Find the radius of a triangle’s inscribed circle from its side lengths.
Triangle Circumradius Calculator
Find the radius of the circle through all three triangle vertices.
Triangle Median Calculator
Find a triangle median length from its three side lengths.
Can I use the sloping side as triangle height?
Only if it is perpendicular to the chosen base. A general sloping side is not the perpendicular height.
Useful next steps in other categories
Roof Pitch Calculator
Find a roof angle from its vertical rise and horizontal run.
Ramp Length Calculator
Calculate inclined ramp length from vertical rise and horizontal run.
More geometry topics
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Calculate curved areas, arcs, chords and circular borders.
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Measure areas and outlines of rectangles, kites and regular polygons.
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Find capacity and outside area for common three-dimensional shapes.
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Calculate distances and vector relationships in two or three dimensions.
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