Home Back

Side of Triangle Calculator

Side Calculation Formula:

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

meters
degrees
degrees
meters

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is a Side of Triangle Calculator?

Definition: This calculator determines the length of an unknown side of a triangle using the Law of Sines when you know one side length and two angles.

Purpose: It helps in trigonometry problems, engineering calculations, and geometric constructions where triangle side lengths need to be determined.

2. How Does the Calculator Work?

The calculator uses the Law of Sines formula:

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

Which can be rearranged as:

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

Where:

Explanation: The ratio of any side length to the sine of its opposite angle is constant for all sides and angles in a triangle.

3. Importance of Triangle Side Calculation

Details: Accurate side length calculations are essential in fields like surveying, navigation, architecture, and physics where triangular relationships are common.

4. Using the Calculator

Tips: Enter the known side length, the angle opposite the unknown side, and the angle opposite the known side. All angles must be between 0° and 180° and their sum must be less than 180°.

5. Frequently Asked Questions (FAQ)

Q1: What if I have two sides and one angle?
A: Use the Law of Cosines calculator instead for that configuration.

Q2: Why does my calculation show an error?
A: Ensure the sum of your two angles is less than 180° and all values are positive.

Q3: Can I use this for right triangles?
A: Yes, but you could also use simpler right triangle trigonometry (SOHCAHTOA).

Q4: What units should I use?
A: Any consistent length unit (meters, feet, etc.) works for side lengths. Angles must be in degrees.

Q5: How accurate is this calculation?
A: The calculation is mathematically precise, but real-world accuracy depends on your input measurements.

Side of Triangle Calculator© - All Rights Reserved 2025