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Online Triangle Calculator

Enter any valid input (3 side lengths, 2 sides and an angle or 2 angle and a 1 side) and our calculator will do the rest. (More info on how the tool works)

Your 3 side lengths ( ) are invalid .

Side Lengths of do not adhere to the triangle inequality theorem. which states that the sum of the side lengths of any 2 sides of a triangle must exceed the length of the third side. Read more about this rule here.
Test Case triangle-calculator/online.php
 Case Meaning 1 3,4,5 ,right 2 right triangle 3 tri inequality theorem 4 1 valid obtuse triangle 5 1 valid actue triangle 6 1 valid obtuse triangle 7 1 valid actue 8 Right triangle angle error 9 2 distinct triangles 10 inequality 11 2 distinct triangles 12 2 angles given only (3rd already known, what to do?)
Status: Calculator waiting for input

Triangle 1

 Sides Angles Side A $$\angle$$ A Side B $$\angle$$ B Side C $$\angle$$ C

Second Triangle

 Sides Angles Side A $$\angle$$ A Side B $$\angle$$ B Side C $$\angle$$ C