Curve Fitting - HP -11C Owner's Handbook Manual

Section 10: Applications Programs 169
Triangle Solutions
This program may be used to find the sides, the angles, and the
area of a plane triangle.
S S»
As Aj
S3
In general, the specification of any three of the six parameters of a
triangle (3 sides, 3 angles) is sufficient to define a triangle. (The
exception is that three angles will not define a triangle). There are
thus five possible cases that this program will handle: two sides
and the included angle (SAS), two angles and the included side
(ASA), two sides and the adjacent angle (SSA—an ambiguous
case), two angles and the adjacent side (AAS), and three sides
(SSS).
If the three known input values are selected in a clockwise order
around the triangle, the outputs will also follow a clockwise order.
Remarks:
e Inputs may be in any angular mode (i.e., DEG, RAD, GRAD).
Be sure to set the angular mode of the calculator to match that
of the inputs.
e Note that the triangle described by the program does not
conform to standard triangle notation; i.e., A; is not opposite
S,.
¢ Angles must be entered as decimals. The [g] conversion
can be used to convert degrees, minutes, and seconds to
decimal degrees.
e Accuracy of solution may degenerate for triangles containing
extremely small angles.