Last updated: July 31, 2026
AAS Triangle Calculator
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Creators
Dharmendra SinghReviewers
Formula
C = 180° - A - B; a/sin(A) = b/sin(B) = c/sin(C)
Where:
- A,B,C=Triangle angles(°)
- a,b,c=Opposite side lengths
Worked Examples
Known side a with two angles
Solve with A=50°, B=60°, and a=10.
- 1Compute C = 180 - 50 - 60 = 70°
- 2Use Law of Sines ratio based on known side a
- 3Find b ≈ 11.305159 and c ≈ 12.266816
- 4Compute perimeter and area from solved sides
Known side b gives right triangle
Solve with A=30°, B=60°, and b=8.
- 1C = 90°
- 2Use b/sin(B) to scale side a and c
- 3Classify type from angles
Known side c with obtuse angle
Solve with A=100°, B=30°, and c=9.
- 1C = 50°
- 2Use c/sin(C) as ratio
- 3Compute a and b and classify by largest angle
Introduction
This AAS triangle calculator solves a triangle from two angles and one known non-included side. It computes the third angle, all sides, area, perimeter, and triangle classification using the Law of Sines.
Formula and Method
The AAS Triangle Calculator uses the core relation C = 180° - A - B; a/sin(A) = b/sin(B) = c/sin(C).
Apply the formula directly to user inputs
Compute intermediate terms when needed
Round numeric outputs for stable display
Return structured outputs for UI rendering
Input Fields
Provide values for: angleA, angleB, knownSide, knownSideValue.
- 1
angleA: Angle A (degrees)
- 2
angleB: Angle B (degrees)
- 3
knownSide: Known side
- 4
knownSideValue: Known side length
Output Fields
The calculator returns: sideA, sideB, sideC, angleC, area, perimeter, triangleType.
- 1
sideA: Solved side opposite angle A
- 2
sideB: Solved side opposite angle B
- 3
sideC: Solved side opposite angle C
- 4
angleC: Third angle from angle sum
- 5
area: Triangle area
- 6
perimeter: Sum of all sides
- 7
triangleType: Acute, right, or obtuse
Validation Rules
Angles must be positive with angleA + angleB < 180°, and knownSideValue must be positive.
Invalid or missing numeric values trigger safe fallback outputs
Error messaging is returned by the calculation function when constraints fail
Domain restrictions are enforced before formula evaluation
Rounding is applied to final numeric values
How to Use This Calculator
Enter valid inputs, run the calculation, and review both primary and supporting outputs.
Enter each required field
Click calculate
Check primary output first
Use examples to verify expected behavior
Practical Uses
This calculation is commonly used in math practice, engineering checks, and fast verification tasks.
Homework and exam preparation
Quick sanity checks while modeling
Teaching and tutoring demonstrations
Reusable reference for manual calculations
FAQs
What does the AAS Triangle Calculator compute?
It computes sideA, sideB, sideC, angleC, area, perimeter, triangleType from the provided inputs.
Which inputs are required?
Required fields are angleA, angleB, knownSide, knownSideValue.
How are results rounded?
Numeric outputs are rounded by the calculation function (generally to about 6 decimal places) for cleaner display.
What if I enter invalid values?
Angles must be positive with angleA + angleB < 180°, and knownSideValue must be positive.
Which output should I read first?
Start with sideA, then use the remaining outputs for context and interpretation.
Can I use decimal values?
Yes. Decimal inputs are supported unless the calculator specifically requires integer-style values.