Home Back

Law of Sines Calculator

Law of Sines Formula:

\[ \frac{a}{\sin A} = \frac{b}{\sin B} \]

units
units

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Law of Sines?

The Law of Sines is a trigonometric formula relating the lengths of sides of a triangle to the sines of its opposite angles. It states that the ratio of the length of a side to the sine of its opposite angle is constant for all three sides and angles in a triangle.

2. How Does the Calculator Work?

The calculator uses the Law of Sines formula:

\[ \frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} \]

Where:

Explanation: The calculator can find missing sides or angles when you provide at least one complete ratio (side and its opposite angle) plus one other element.

3. Applications of the Law of Sines

Details: The Law of Sines is used in trigonometry and geometry for solving triangles, navigation, astronomy, and various engineering applications where triangular relationships are involved.

4. Using the Calculator

Tips: Enter any three known values (two sides and one angle or two angles and one side). The calculator will compute the missing values. Angles should be in sine values (dimensionless between 0 and 1).

5. Frequently Asked Questions (FAQ)

Q1: When should I use the Law of Sines?
A: Use it when you know either two angles and one side (AAS or ASA) or two sides and an angle opposite one of them (SSA).

Q2: What's the ambiguous case in Law of Sines?
A: For SSA cases, there might be two possible solutions (two different triangles that satisfy the given conditions).

Q3: How does this differ from the Law of Cosines?
A: Law of Cosines relates all three sides and one angle, while Law of Sines relates sides to their opposite angles.

Q4: Can I use this for right triangles?
A: Yes, but in right triangles, simpler trigonometric ratios (SOHCAHTOA) are usually more straightforward.

Q5: What units should I use?
A: Side lengths can be in any units as long as they're consistent. Angle inputs should be sine values (dimensionless).

Law of Sines Calculator© - All Rights Reserved 2025