Triangle Calculator (Complete)
With this comprehensive triangle calculator, you can easily calculate unknown sides, angles, area, perimeter and heights for almost any triangle. Choose the calculation method you need, enter the known values, and the calculator instantly calculates all remaining properties. The results are clearly displayed and supported by a clear diagram of the triangle.
Result
Visualization
Formula used
Which calculations does this calculator support?
This triangle calculator supports several ways to solve a triangle. Depending on the information you already know, choose the method that best fits your situation.
Visualization
Pythagoras
Use the Pythagorean theorem for right triangles. It allows you to calculate the hypotenuse or a missing leg.
SSS (Side – Side – Side)
When all three sides are known, the calculator automatically calculates all three angles, the area, perimeter and heights.
SAS (Side – Angle – Side)
When two sides and the included angle are known, the third side is first calculated using the cosine rule. The remaining angles and properties are then also determined.
ASA (Angle – Side – Angle)
When two angles and the included side are known, the calculator first calculates the third angle and then the missing sides using the sine rule.
AAS (Angle – Angle – Side)
When two angles and a non-included side are known, the missing angle is calculated first. The remaining sides are then determined using the sine rule.
Sine Rule
The sine rule is suitable when you know a side and its opposite angle, as well as an additional side or angle. It can be used to calculate missing sides or angles.
Cosine Rule
The cosine rule is used when three sides are known, or when two sides and the included angle are known. It can be used to calculate unknown sides or angles.
Which properties are calculated?
In addition to the requested sides and angles, the calculator automatically calculates:
- all three sides;
- all three angles;
- the area;
- the perimeter;
- the three heights;
- the type of triangle (equilateral, isosceles, right-angled or scalene).
The triangle is also displayed visually, so you can immediately see which side or angle corresponds to the calculated value.
Formulas
Depending on the selected method, the calculator uses the following formulas, among others:
Pythagorean Theorem
c² = a² + b²
Sine Rule
a / sin(A) = b / sin(B) = c / sin(C)
Cosine Rule
c² = a² + b² − 2ab · cos(C)
Area
Area = (base × height) / 2
Perimeter
Perimeter = a + b + c
Frequently Asked Questions
Can I calculate any triangle?
Yes. The calculator supports the most commonly used calculation methods for right, isosceles, equilateral and general triangles.
Can I calculate angles only?
Yes. Depending on the values entered, the calculator can calculate missing angles using the sine rule, cosine rule or the angle sum of a triangle.
How accurate are the results?
The calculations are performed with high numerical accuracy. The displayed results are rounded for a clear presentation.
Is the triangle also drawn?
Yes. In addition to the calculated values, a to-scale SVG diagram is displayed. This lets you immediately see which sides and angles correspond to the calculated results.