Non Right Angle Triangle Calculator

Calculator Inputs

Side a

Side b

Side c

Angle A in degrees

Angle B in degrees

Angle C in degrees

Decimal precision

Formula Used

Law of Sines: a / sin(A) = b / sin(B) = c / sin(C). This is used for ASA, AAS, and SSA patterns.

Law of Cosines: c² = a² + b² - 2ab cos(C). Similar forms solve sides a and b. Angle form uses cos(A) = (b² + c² - a²) / 2bc.

Angle Sum: A + B + C = 180°. The missing angle equals 180° minus the two known angles.

Heron Area: s = (a + b + c) / 2. Area = √[s(s - a)(s - b)(s - c)].

Extra Measures: height = 2 × area / side. Inradius = area / s. Circumradius = abc / (4 × area).

How to Use This Calculator

Label sides a, b, and c opposite angles A, B, and C.
Enter any valid SSS, SAS, ASA, AAS, or SSA measurements.
Leave unknown fields blank. Do not enter zero values.
Select the required decimal precision.
Press the calculate button to show results above the form.
Use CSV or PDF buttons when you need saved output.

Example Data Table

Pattern	Input	Main Output	Use Case
SSS	a = 7, b = 8, c = 9	Area about 26.83	All sides are known.
SAS	a = 10, b = 14, C = 55°	Side c is solved first.	Two sides include one angle.
ASA	A = 45°, B = 65°, a = 12	C equals 70°.	Two angles and one side are known.
SSA	a = 8, b = 9, A = 40°	Two solutions may appear.	Ambiguous oblique triangle data.

About This Oblique Triangle Tool

Non right angle triangles appear in surveying, design, navigation, mapping, roof work, and classroom geometry. They are also called oblique triangles. Their angles do not rely on a simple perpendicular side pair. Because of that, one fixed method rarely works for every case.

Why This Calculator Helps

This calculator accepts sides, angles, or mixed known values. It checks common solving patterns, including SSS, SAS, ASA, AAS, and SSA. The SSA case can create two valid triangles. The result area shows both when the data allows them. That helps users avoid a common ambiguous case mistake.

The tool also validates triangle rules. Sides must satisfy the triangle inequality. Angles must form a total of 180 degrees. Values must stay positive. These checks protect the final answer from impossible input.

What Results Mean

The output gives missing sides and missing angles first. It then adds perimeter, semiperimeter, area, heights, medians, inradius, and circumradius. These values make the page useful for more than homework. They can support estimates, diagrams, reports, and planning notes.

The classification line explains the shape in plain words. It can mention acute, obtuse, right-like, scalene, isosceles, or equilateral behavior. A non right angle triangle usually becomes acute or obtuse. If a value is very close to 90 degrees, the calculator warns that the data is nearly right angled.

Practical Use

Enter only the measurements you trust. Leave unknown boxes blank. Choose a suitable precision level. Then run the calculation. Read any notes before using the numbers in final work. Small rounding changes can affect long sides, small angles, and area values.

For best results, keep units consistent. If one side is in meters, all sides should use meters. Angles should be entered in degrees. The calculator does not require a drawing, but a sketch can help you identify opposite sides and included angles before entering values.

Export and Review

After solving, download a table as CSV or a simple PDF. These files are helpful when you need to attach results to notes or share them with a teacher, client, or teammate. The example table shows sample inputs and expected outputs, so you can compare your own values before trusting a final answer confidently today.

FAQs

1. What is a non right angle triangle?

It is a triangle that does not have a 90 degree angle. It may be acute or obtuse. The calculator still warns you when entered values make the triangle nearly right angled.

2. Which input patterns are supported?

The calculator supports SSS, SAS, ASA, AAS, and SSA. These cover most oblique triangle problems. Enter only known measurements, and leave the remaining boxes blank.

3. Why can SSA show two answers?

SSA can be ambiguous because the same data may form two different triangles. When both are valid, the calculator lists both solutions separately for safer review.

4. Can I enter all three sides?

Yes. Enter sides a, b, and c. The calculator uses the Law of Cosines to find angles, then calculates area, heights, medians, and radius values.

5. What units should I use?

Use one consistent unit for all side lengths. You can use meters, inches, feet, or any other length unit. Area will use that unit squared.

6. Why did I get an error?

An error appears when values cannot form a valid triangle. Common causes include negative values, angles totaling 180 degrees or more, and impossible side lengths.

7. What does the CSV button do?

The CSV button downloads the solved values in a spreadsheet friendly format. It is useful for records, reports, checking examples, and sharing calculations.

8. What does the PDF button do?

The PDF button downloads a simple result sheet. It includes solved sides, angles, area, perimeter, classification, and notes for the current calculation.