- Open DrJava and expand the Interactions pane.
- Type the following, remember DrJava interprets statements through the semi-colon, typing a variable name and pressing the return key is interactively telling the Interactions pane to echo the value.

> double root = Math.sqrt(17.0); > root 4.123105625617661 > double angle = 1.5; > double height = Math.sin(angle); > height 0.9974949866040544

- Type the following three lines in the Interactions pane.

> double degrees = 90; > double angle = degrees/180.0 * Math.PI; > angle 1.5707963267948966

- Type the following two lines in the Interactions pane.

> long x = Math.round(Math.PI * 20.0); > x 63