Triangle Angle Sum Calculator
How It Works
This triangle angle sum calculator uses established formulas to provide accurate results.
The basic rule:
- A + B + C = 180°
- C = 180° - A - B
Results are estimates. Consult a professional for critical decisions.
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Explore Allday Everyday Math →Frequently Asked Questions
Why do triangle angles always sum to 180°?
In Euclidean geometry, the interior angles of any triangle always sum to exactly 180° (or π radians). This is a fundamental property that follows from the parallel postulate.
What is an acute triangle?
An acute triangle has all three angles less than 90°. Examples include equilateral triangles (all 60°) and any triangle where the largest angle is less than 90°.
What is an obtuse triangle?
An obtuse triangle has one angle greater than 90°. A triangle can have at most one obtuse angle because the other two must sum to less than 90° to keep the total at 180°.
Can a triangle have two right angles?
No. If two angles were each 90°, they would sum to 180° leaving 0° for the third angle, which is impossible. A triangle can have at most one right angle.