Type the two sides of a right triangle you know and this program gives you the third, whether that's the hypotenuse or a missing leg.
Send it to your calculator
Plug the calculator into your computer with a USB cable, then use the button below.
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Open it on the calculator
Press the prgm key. It sits in the middle of the keyboard, two rows below the arrow keys.
The PROGRAMMING menu opens with TI-Basic already highlighted. Press enter.
PYTHAG is in the program list. Press enter to pick it, which puts prgmPYTHAG on the home screen, then enter again to run it.
Find the hypotenuse
The program opens with a menu asking which side of the triangle you're missing.
Press enter to choose Hypotenuse. The program asks for the two legs, one at a time. Type each leg and press enter after it. For legs of 3 and 4, the moment you enter the second one it answers Hypotenuse=5.
Find a missing leg
Run the program again: press prgm, choose TI-Basic, then pick PYTHAG from the list and run it with enter.
This time scroll down to A leg and press enter. Now it asks for the leg you know, then the hypotenuse. With a leg of 5 and a hypotenuse of 13, it fills in Other leg=12.
Good to know
- It's the Pythagorean theorem, worked out for you. The program solves a² + b² = c² for whichever side you asked about: √(a² + b²) for the hypotenuse, √(c² − a²) for a leg.
- Sides don't have to be whole numbers. Decimals work at every prompt: legs of 1.5 and 2 give Hypotenuse=2.5.
- Answers that aren't whole come out as decimals. Legs of 2 and 4 give 4.472135955 rather than the exact √20. If you want the tidy radical form, the Radical Simplifier program turns 20 into 2√5.
- Rerun it with one keypress. Pressing enter on the home screen repeats whatever you ran last, so right after a run, a single enter brings the menu straight back.
- The hypotenuse is always the longest side. In the A leg option, if the leg you type is as long as the hypotenuse or longer, the program answers "Hypotenuse must be longest" instead of dropping you on an error screen.
- A calculator reset removes it. TI-Basic programs live in RAM, so if the program disappears after a reset, just send it again from this page.
