TI Program: Law of Sines/Cosines Instructions

How to get the program

TI-82/83/84

Click here to see the program
If you have the TI-Graph link to send programs from your computer to your calculator, then you can save the UUE Encoded file as text in your web browser. Next have the TI Graph Link software "UUE Decode" the text file. For help and information about this, go to www.ticalc.org, Texas Instruments or www.ti-files.org's FAQ

TI-85/86

Click here to see the program
If you have the TI-Graph link to send programs from your computer to your calculator, then you can save the UUE Encoded file as text in your web browser. Next have the TI Graph Link software "UUE Decode" the text file. For help and information about this, go to www.ticalc.org, Texas Instruments or www.ti-files.org's FAQ

TI-89/92

Click here to see the program
If you have the TI-Connect link to send programs from your computer to your calculator, then you can use law89.zip. TI Graph Link software "UUE Decode" the text file. For help and information about this, go to www.ticalc.org, Texas Instruments or www.ti-files.org's FAQ

How to use the program

Every triangle (in a plane), has six characteristics: three sides and three angles. If you know some combination of 3 sides or angles of any triangle, you may use the Law of Sines or the Law of Cosines to find the other three. This program uses menus to direct you to the correct application of either the Law of Sines or the Law of Cosines. Select the combination of what you know, and it will determine the measure of the rest.

For example, if you know the measure of two sides of a triangle and you also know the measure of the angle in between, you would choose SAS (for Side-Angle-Side). The program LAW will then prompt you for these dimensions in this same order (side-angle-side), and then it will display the measure of the remaining side and the other two angles.

Some versions of this program also has Heoron's formula for finding the area of a triangle, provided that you know the measures of the three sides.