How to switch to degree mode on a TI-89 Titanium

By E-Code · updated 2026-09-27

Press MODE, ▼ three times to Angle, ▶ to open the choices, 2 for DEGREE and ENTER to save. Angles are then read in degrees, so sin(30) gives 1/2.

Step by step

1. Open MODE. MODE Press MODE. Page 1 lists Graph, Current Folder, Display Digits, Angle and more.
2. Go to Angle. ▼ ▼ ▼ Press ▼ three times to reach Angle. It says RADIAN, the factory setting.
3. Open the choices. ▶ Press ▶. A list opens: 1 RADIAN, 2 DEGREE, 3 GRADIAN.
4. Pick DEGREE. 2 Press 2 for DEGREE.
5. Save it. ENTER Press ENTER to save and close MODE. ESC would throw the change away. The status line now says DEG.
6. Type sin(30). 2nd Y 3 0 ) Press 2nd Y for sin(, then 30 and ).
7. Work it out. ENTER Press ENTER. 30 now means 30 degrees.
8. Read the answer. sin(30°) = 1/2. Set Angle back to RADIAN for calculus, where angles are always in radians.

What the screen shows

sin(30°) = 1/2. Set Angle back to RADIAN for calculus, where angles are always in radians.

Look for 1/2 on the screen.

Try it with the keys lit up

This guide is one of E-Code's Learn lessons. Open it on E-Code's TI-89 calculator and each key lights up in turn as you press it.

Try “Switch to degree mode” on the TI-89 calculator

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