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### Construction of Circles

The different ways to generate circles respectively arcs of circles are:

Figure 45: Characterizations for circle construction

Exercise (CREATE CIRCLE CTRR): Generate an arbitrary point named P1 , then construct a circle with radius= 55 centered on P1.
Solution: After generating your point P1, click the icons for the command CREATE CIRCLE CTRR. For the mandatory parameter CTR (center), either enter the name of P1 in the command line, or select this point. After that, you enter the value of the radius R on the displayed numeric keypad.

Figure: CREATE CIRCLE CTRR

Exercise (CREATE CIRCLE CTRE): Generate one more point named P2. Construct a circle centered on P1 and running through P2.
Solution: After producing P2 and entering P1 for center in the command CREATE CIRCLE CTRE, click the icon for the mandatory parameter ENT (entity). A range of possible objects that can be used for this parameter is displayed. In this exercise, the circle is touching a point. Click the icon, and approach point P2 with the cursor. The circle is already hanging at the cursor. Select point P2 and conclude the command with the right mouse button.

Figure: CREATE CIRCLE CTRE

Exercise (CREATE CIRCLE EER): Generate 2 line segments named G1 and G2 at right angles, and then construct the inner circle to the segments with radius= 8 .
Tip: When solving this exercise, it may be useful to turn the pick circle off.
Solution:
After producing the line segments G1 and G2, click the icons for the command CREATE CIRCLE EER. If then you choose the mandatory parameters ENT1 and ENT2 , a choice of possible object types is generated for each one, similarly to the preceding exercise. In our example, it will be the two line segments. After that, you enter the value of the radius R on the displayed numeric keypad. SISCAD-P then displays all possible circles, and you can select the intended one(s) with the optional parameter SEL (selection).

Figure: CREATE CIRCLE EER

Next: Filleting Up: Basic Constructions and Previous: Construction of Line