HP 39gs Graphing manual Triangle Solve aplet, About the Triangle Solver aplet

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Triangle Solve aplet

About the Triangle Solver aplet

The Triangle Solver aplet allows you to determine the length of a side of a triangle, or the angle at the vertex of a triangle, from information you supply about the other lengths and/or other angles.

You need to specify at least three of the six possible values—the lengths of the three sides and the size of the three angles—before the solver can calculate the other values. Moreover, at least one value you specify must be a length. For example, you could specify the lengths of two sides and one of the angles; or you could specify two angles and one length; or all three lengths. In each case, the solver will calculate the remaining lengths or angles.

The hp39gs will alert you if no solution can be found, or if you have provided insufficient data.

If you are determining the properties of a right-angled triangle, a simpler input form is available by pressing the menu key.

Note that the Triangle Solver aplet only has a numeric view.

Getting started with the Triangle Solver aplet

The following example solves for the unknown length of the side of a triangle whose two known sides—of lengths 4 and 6—meet at an angle of 30 degrees.

Before you begin: You should make sure that your angle measure mode is appropriate. If the angle information you have is in degrees (as in this example) and your current angle measure mode is radians or grads, change the mode to degrees before running the solver. (See “Mode settings” on page 1-10 for instructions.) Because the angle measure mode is associated with the aplet, you should start the aplet first and then change the setting.

Triangle Solve aplet 9-1