AAA Triangle Calculator

Calculate the third angle in a triangle and analyze triangle properties

Triangle Angle Calculator

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Triangle Analysis

Example Calculations

Right Triangle Example

Given: α = 30°, β = 90°

Find: γ = ?

Solution: γ = 180° - 30° - 90° = 60°

Result: This is a 30-60-90 right triangle

Equilateral Triangle Example

Given: α = 60°, β = 60°

Find: γ = ?

Solution: γ = 180° - 60° - 60° = 60°

Result: All angles are equal (equilateral triangle)

Obtuse Triangle Example

Given: α = 100°, β = 40°

Find: γ = ?

Solution: γ = 180° - 100° - 40° = 40°

Result: One angle > 90° (obtuse triangle)

Triangle Types by Angles

A

Acute Triangle

All angles < 90°

Example: 70°, 60°, 50°

R

Right Triangle

One angle = 90°

Example: 90°, 60°, 30°

O

Obtuse Triangle

One angle > 90°

Example: 100°, 50°, 30°

Triangle Facts

📐

Sum of angles always equals 180° (or π radians)

📏

AAA triangles are similar but may have different sizes

🔄

Cannot determine side lengths from angles alone

🎯

Knowing two angles determines the third

Understanding AAA Triangles

What is an AAA Triangle?

An AAA triangle is a triangle where all three angles are known. The "AAA" stands for Angle-Angle-Angle, indicating that we have information about all three interior angles of the triangle.

The Angle Sum Property

The most fundamental property of triangles is that the sum of their interior angles always equals 180° (or π radians in the metric system). This is known as the Triangle Angle Sum Theorem.

Why Can't We Find Side Lengths?

While AAA tells us the shape of the triangle, it doesn't tell us the size. Triangles with the same angles can be scaled to any size, making them similar but not necessarily congruent.

Formula and Calculation

α + β + γ = 180°

α + β + γ = π radians

If you know two angles, you can find the third using:

γ = 180° - α - β

Applications

  • Geometry and trigonometry problems
  • Architecture and engineering design
  • Navigation and surveying
  • Computer graphics and 3D modeling