Oblique Triangle Solutions Calculator & Equations

This calculator will determine the unknown length of a given oblique triangle for an Obtuse or Acute triangle. Simply enter in the unknown value and and click "Update" button located at the bottom of the web page.

OBLIQUE TRIANGLE SOLUTIONS: Input:
Results:
a b c
LA LB LC Area a c LB
b LA LC Area
a c LC
b LA LB Area
a LA LB
b c LC Area
c LA LC
a b LB Area
c LB LC
a b LA Area
Note: Input and results strictly adhere to
side and angle nomenclature above.
Law of Sine's
a/SIN(LA)
Law of Cosines:
a2 = b2 + c2 - 2*b*c*COS(LA)
b2 = a2 + c2 - 2*a*c*COS(LB)
c2 = a2 + b2 - 2*a*b*COS(LC)
For Acute Angle: (all of following are satisfied)
a2 + b2 > c2  ,  b2 + c2 > a2  ,  and  a2 + c2 > b2
For Obtuse Angle: (only one of following is satisfied
either  a2 + b2 < c2  ,  or  b2 + c2 < a2  ,  or  a2 + c2 < b2
Area of Triangle:
Area = a*c*SIN(LB)/2 = b*c*SIN(LA)/2 = a*b*SIN(LC)/2  © Copyright 2000 - 2019, by Engineers Edge, LLC www.engineersedge.com Membership Register | Login   Home Engineering Book Store Engineering Forum Excel App. Downloads Online Books & Manuals Engineering News Engineering Videos Engineering Calculators Engineering Toolbox GD&T Training Geometric Dimensioning Tolerancing DFM DFA Training Training Online Engineering Advertising Center Copyright Notice 