**Angles**

Angles are applied in two primary modes: degrees and radians. Set up the mode
accordingly. Press **MENU 1** to access the RUN-MAT
screen.

**Warning** Most calculator
errors in trigonometry occur because the calculator is in the wrong angle set
up mode.

To
set up the angle mode, press **CTRL****
SETUP** (located above the F3 key). Navigate to **Angle**. Press **F1**
to select Deg for degree mode or press **F2** to select Rad for radian mode.
We also recommend that Display be set to Normal (press the thumb pad down arrow
several times to locate Display). After set up, press **EXE**
to return to the RUN-MAT home screen.

**Degree
Mode**

In degree mode, angles can be entered as decimal degrees (DD) or degress-minutes-seconds (DMS). For example, to evaluate tan(17°43'25"), press

tan (1 7 OPTN F6(to see more options)F3(to access ANGL)4(to select a DMS entry)4 3 F3 42 5 F3 4) EXE

While in degree mode, you can convert radians to degrees. For example, to convert 1.23 radians to degrees, press

**
1 . 2 3**

** F3 **(to access ANGL) [if needed, **OPTN F6** to see ANGL]

** 2 **(to select 2:^{r} )

** EXE** [Hence, 1.23^{r} 70.4738°.]

**Radian Mode**

Set the calculator to RADIAN mode. Radian angles can then be entered as ordinary numbers. For example, to evaluate sin(π/4), press

sin (SHIFT π(located above the EXP key)4 ) EXE

While in radian mode, you can convert degrees to radians. Enter the angle using the DMS symbols. For example, to convert 17°43'25" to radians, press

** 1 7 OPTN F6 F3 4**

**
4 3 F3 4**

** 2 5 F3 4**

** EXE** This converts DMS to DD.

**SHIFT Ans** (located above the (-) key)

**x SHIFT π 1 8 0 EXE**
This converts DD to radians.

Hence, 17°43'25"" .309 radians.