Tuesday

Command:_CIRCLE

Hello,

We will be talking about the CIRCLE command this week. You can access the command drom the Draw toolbar or by typing CIRCLE as a keyboard command. This is what happens in the command prompt when you activate it;

Command:_CIRCLE
CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:
Specify radius of circle or [Diameter] <100.0000>: 100 (I entered 100mm as radius, that means we will have a circle 200mm in diameter.)

Fig.1 Our circle with a 100mm radius.

3P (Tree point) This feature enables you to draw a circle that passes from the three points that you specify.

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:3P (you have to enter 3p to be able to use the feature)

Fig.2 A circle drawn using 3P.

2P(Two point) With this feature, you can draw circles that take any two points you specify as the endpoints of its diameter.

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:2P (you have to enter 2p to be able to use the feature)

Fig.3 A circle drawn using 2P.

TTR(Tangent-Tangent-Radius) This is the one that really fascinates me. All in all, you use this to draw a circle that lies tangent to two lines, with any given radius. This feature enables us to use a single command to draw a given circle instead of four. Lets add another circle to the ones staying side by side in Fig.4 (Please see Drawing complex curves by using only the CIRCLE Command article.)

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:T (Specify that you want to use this feature using Ttr)
Specify point on object for first tangent of circle: (our first point)
Specify point on object for second tangent of circle: (our second point)
Specify radius of circle <100.0000>: (the radius of the circle)

Fig.4 A circle drawn using Ttr.

Regards