Triangle Calculator
Solve any triangle given SSS, SAS, ASA, or AAS.
Enter all three sides (a, b, c)
5
Side a
6
Side b
7
Side c
44.4153°
Angle A (°)
57.1217°
Angle B (°)
78.463°
Angle C (°)
14.6969
Area
18
Perimeter
About This Tool
The Triangle Calculator solves all sides, angles, area, and perimeter of a triangle from any valid combination of known values (SSS, SAS, ASA, AAS). It uses the Law of Cosines and Law of Sines.
All calculations run in the browser in real time. Four solving modes are supported: three sides, two sides and an angle, two angles and a side, and two angles and a non-included side.
How to Use
- Select the solving method (SSS, SAS, ASA, AAS) using the tabs.
- Enter the required side lengths and angles as prompted by the hint.
- Results appear instantly — the remaining sides, angles, area, and perimeter.
- If the inputs do not form a valid triangle, an error message is shown.
Use Cases
Students verify trigonometry homework. Engineers calculate member lengths in truss structures. Surveyors compute areas from measured distances. Navigators solve triangles for bearing and distance problems.
FAQ
- What do SSS, SAS, ASA, and AAS mean? — They describe which parts of the triangle are known. S = Side, A = Angle. The order indicates how the known values are arranged.
- What formulas are used? — SSS uses the Law of Cosines to find angles. SAS also uses Law of Cosines. ASA and AAS use the Law of Sines.
- Do inputs need units? — No units are assumed — use any consistent unit for side lengths (cm, m, ft). Angles are always in degrees.