Oblique Triangle
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 (m2, mm2, ft2, in2 .....):
A, B and a is known, calculate
b = a sin(B) / sin(A) (1a)
C = 180o - (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 = 180o - (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= 180o - (A + C) (3b)
c = a sin(C) / sin(A) (3c)
a, b and c is known, calculate
cos(A) = (b2 + c2 - a2) / (2 b c) (4a)
cos(B)= (a2 + c2 - b2) / (2 a c) (4b)
C = 180o - (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 = a2 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.