Oblique Triangle
Calculate oblique triangles.
An oblique triangle is any triangle that is not a right angled triangle.
Triangle Three Known Values  Length and Angle Calculator
Calculate the unknown lengths and angles in a triangle. Add three known values  leave the rest of the inputs blank.
Note!  the calculator is based on the same value combinations used in the equations below. Other value combinations will not work  most triangles with three known values can be adapted to these equations. The calculator is quite simple. With strange results  check your input values.
Area (m^{2}, mm^{2}, ft^{2}, in^{2} .....):
(enable popup)
A, B and a is known, calculate
b = a sin(B) / sin(A) (1a)
C = 180^{o}  (A + B) (1b)
c = a sin(C) / sin(A) (1c)
A, a and b is known, calculate
sin(B) = b sin(A) / a (2a)
C = 180^{o}  (A + B) (2b)
c = a sin(C) / sin(A) (2c)
a, b and C is known, calculate
tan(A) = a sin(C) / (b  a cos(C)) (3a)
B= 180^{o}  (A + C) (3b)
c = a sin(C) / sin(A) (3c)
a, b and c is known, calculate
cos(A) = (b^{2} + c^{2}  a^{2}) / (2 b c) (4a)
cos(B)= (a^{2} + c^{2}  b^{2}) / (2 a c) (4b)
C = 180^{o}  (A + B) (4c)
a, b, c, A, B and C is known, calculate area
s = (a + b + c) / 2 (5a)
area = (s (s  a) (s b) (s  c))^{1/2} (5b)
area = b c sin(A) / 2 (5c)
area = a^{2} sin(B) sin(C) / (2 sin(A)) (5d)
Related Topics

Mathematics
Mathematical rules and laws  numbers, areas, volumes, exponents, trigonometric functions and more.
Related Documents

Algebraic Expressions
Principal algebraic expressions formulas. 
Angle Calculator  Carpenter's Square
Calculate angles with a straight board across carpenter's square. 
Geometric Shapes  Areas
Areas, diagonals and more  of geometric figures like rectangles, triangles, trapezoids .. 
Hyperbolic Functions
Exponential functions related to the hyperbola. 
Law of Tangents
Triangles and law of tangents. 
Laws of Indices
Simplifying calculations by involving indices. 
Miter Saw  Calculate Sawing Angle
Calculate miter saw protractor angles for skirting and decorative mouldings work. 
Pythagorean Theorem
Verifying square corners. 
Regular Polygons
Areas of regular polygons  polygons with 3 to 12 sides. 
Right Angled Triangle
Right angled triangle equations. 
Triangle
Triangle analytical geometry. 
Trigonometric Functions
Sine, cosine and tangent  the natural trigonometric functions. 
Vector Addition
Online vector calculator  add vectors with different magnitude and direction  like forces, velocities and more.