The "Reset" button clears all calculations on the page and reinstalls default values (this button may not respond in the FireFox browser).
Reset can also be achieved by pressing the "F5" key.
The Calculate button calculates the associated option only.
Hover your cursor over the symbols for an associated description.
Right-angle triangles are essentially the 'x,y' co-ordinates of the moving end of a line rotated about a central point. The angular polarities the moving line makes with the horizon (θ) is listed below:
0° to 90°: Tan(θ) is positive; Sin(θ) is positive; Cos(θ) is positive;
90° to 180°: Tan(θ) is negative; Sin(θ) is positive; Cos(θ) is negative;
180° to 270°: Tan(θ) is positive; Sin(θ) is negative; Cos(θ) is negative;
270° to 0°: Tan(θ) is negative; Sin(θ) is negative; Cos(θ) is positive;
Enter any two values and the other two will be calculated. If you don't delete the values you wish to calculate, this calculator will assume your input date is; 'θ' & 'h'.
Enter any three values and the other three will be calculated. If you don't delete the values you wish to calculate, this calculator will assume your input date is the three sides; 'A', 'B' & 'C'.
You will notice that some calculations generate an additional (alternative) triangle (alternative result). This usually occurs for calculations with inputs of one angle and two sides; inputs of two angles and one side (length) should not do so.
Whilst the alternative configuration is perfectly valid, given the input data entered, it may result in negative angles and/or lengths.
A negative length means that the side concerned runs in the opposite direction to that shown in the figure.
A negative angle means that two of the sides have crossed each other; generating two triangles.
Full downloadable version of this calculator is available from this website at; Trig.Return to the top of the page