Law of Sines Calculator

Use our free law of sines calculator to solve any triangle. Supports AAS, ASA, and SSA input modes.

Math

Input Mode

Angle A

Angle B

Side a (opposite A)

Side b (opposite B)

Side c (opposite C)

Formula

The law of sines states that the ratio of a side length to the sine of its opposite angle is constant for all three sides of a triangle.

a/sin(A) = b/sin(B) = c/sin(C)

Percentage: The percentage value you want to apply

Number: The original number or value

Result: The calculated result

How It Works

1Select the input mode (AAS, ASA, or SSA).
2Enter the known angles and sides.
3Click Calculate to find the missing values.

Examples

AAS: A=40°, B=60°, a=7

1.C=180-40-60=80°
2.k=7/sin(40°)≈10.89
3.b=10.89×sin(60°)≈9.43
4.c=10.89×sin(80°)≈10.73

Result: 10.7288

ASA: A=50°, B=70°, c=10

1.C=180-50-70=60°
2.k=10/sin(60°)≈11.55
3.a=11.55×sin(50°)≈8.85
4.b=11.55×sin(70°)≈10.85

Result: 10.0000

Frequently Asked Questions

a/sin(A) = b/sin(B) = c/sin(C) for any triangle.

Two angles and a side opposite one of them.

Two angles and the side between them.

Two sides and an angle not between them (ambiguous case).

A + B + C = 180° for any triangle.

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CalculateMe Team

Last updated: 2026-07-14

Law of Sines Calculator

Formula

How It Works

Examples

AAS: A=40°, B=60°, a=7

ASA: A=50°, B=70°, c=10

Frequently Asked Questions

What is the law of sines?

What is AAS?

What is ASA?

What is SSA?

Angle sum?

Related Calculators

Law of Sines Calculator

Formula

How It Works

Examples

AAS: A=40°, B=60°, a=7

ASA: A=50°, B=70°, c=10

Frequently Asked Questions

What is the law of sines?

What is AAS?

What is ASA?

What is SSA?

Angle sum?

Related Calculators