! Display a figure consisting of three concentric circles,

! of radii 10, 20, and 30 units,

! all centered at the center of the screen.

SET MODE "GRAPHICS"

LET Ratio = 1.4

SET WINDOW -(50*Ratio),(50*Ratio),-50,50

OPTION ANGLE degrees

SET COLOR "red"

DRAW Circle(10,0,0)

SET COLOR "green"

DRAW Circle(20,0,0)

SET COLOR "blue"

DRAW Circle(30,0,0)

SET COLOR "brown"

PLOT TEXT, AT -15,-40: "Concentric circles"

SOUND 1000,.2

END

PICTURE Circle (R, X, Y)

! Draw a circle of radius R at point X, Y

BOX CIRCLE X-R, X+R, Y-R, Y+R

END PICTURE

The result:

Three concentric circles of different colors