Home Back

Side To Angle Calculator Triangle

Angle Calculation Formula:

\[ \text{Angle} = \arccos\left(\frac{b^2 + c^2 - a^2}{2bc}\right) \]

units
units
units

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Side to Angle Calculator?

The Side to Angle Calculator determines an angle in a triangle when you know the lengths of all three sides, using the Law of Cosines. This is particularly useful in trigonometry and geometry problems.

2. How Does the Calculator Work?

The calculator uses the Law of Cosines formula:

\[ \text{Angle} = \arccos\left(\frac{b^2 + c^2 - a^2}{2bc}\right) \]

Where:

Explanation: The formula relates the lengths of the sides of a triangle to the cosine of one of its angles.

3. Importance of Angle Calculation

Details: Calculating angles from side lengths is fundamental in trigonometry, navigation, engineering, and computer graphics. It allows solving triangles when only side lengths are known.

4. Using the Calculator

Tips: Enter all three side lengths in the same units. The side labeled 'a' should be opposite the angle you want to calculate. All values must be positive numbers that satisfy the triangle inequality (sum of any two sides must be greater than the third).

5. Frequently Asked Questions (FAQ)

Q1: What if I get an error message?
A: The error means your side lengths cannot form a triangle. Check that the sum of any two sides is greater than the third.

Q2: Can I calculate all angles of a triangle this way?
A: Yes, you can calculate all three angles by changing which side you consider as 'a' in the formula.

Q3: What units should I use?
A: Any consistent units (cm, inches, etc.) as long as all three sides use the same unit.

Q4: How accurate is this calculation?
A: The calculation is mathematically exact, though practical accuracy depends on your precise side length measurements.

Q5: Does this work for all types of triangles?
A: Yes, it works for acute, right, and obtuse triangles.

Side To Angle Calculator Triangle© - All Rights Reserved 2025